Donatella Tirindelli Danesi

Radiosensitization by oxaliplatin in a mouse adenocarcinoma: influence of treatment schedule

PURPOSE The aim of our study was to investigate if oxaliplatin (1-OHP) could be used as a radiosensitizer in vivo. MATERIALS AND METHODS Experiments were performed in mice (C3D2F1) bearing a transplanted mammary carcinoma in a foot. Drugs, 1-OHP and cis-diammine-dichloro-platinum (CDDP), were administered i.p. Results were analyzed in terms of tumor growth delay (TGD). RESULTS 1-OHP and CDDP were tested in single doses of 6 and 10 mg/kg body weight. Administration of either 1-OHP or CDDP produced a significant TGD but only with the dose of 10 mg/kg. Single dose combined X-ray (10 Gy) and 1-OHP (6 and 10 mg/kg) treatments were performed with different sequences and time intervals (1 h, 4 h, and 24 h). All TGDs of these combined treatments were uniform among themselves (indicating that sequence and time interval did not influence the results), and did not depend on the drug dose. In X-ray (10 and 20 Gy) and 1-OHP (6 and 10 mg/kg) combined treatment, the TGDs increased only with X-ray dose. Different 1-OHP administration schedules were performed for fractionated experiments: two treatments every 4 days. The least toxic protocol (1-OHP total dose from 6 to 14 mg/kg) was selected for combined treatments with 10 daily X-ray treatments of 2 Gy. A clear drug dose-effect relationship was observed in those treatments with 1-OHP doses from 10 to 14 mg/kg. CONCLUSION Although low-dose 1-OHP did not induce a TGD when administered alone, in combined protocols it increased X-ray efficacy.

DNA/protein flow cytometry as a predictive marker of malignancy in dysplasia-free Barrett's esophagus: Thirteen-year follow-up study on a cohort of patients

Intestinal metaplasia identifies Barretts esophagus (BE) and is associated with an increased risk for esophageal adenocarcinoma. Dysplasia occurs as an intermediate step. However, progression from metaplasia to neoplasia without the demonstration of dysplasia has been described. The role of dual-parameter flow cytometry (FC) as a predictor of neoplastic risk in dysplasia-free cases was evaluated. DNA/protein FC and histology were performed on 362 samples from 30 dysplasia-free BE patients, followed up since 1985 once every 1-2 years. Nine cases were aneuploid, five of which (group IV) were frankly aneuploid; in the other four cases (group III), aneuploidy was detectable by dual-parameter analysis only. Twenty-one patients were diploid. Twelve (group II) also had an abnormally high G1-phase protein content compared to group I (nine patients), which were diploid with a low-moderate protein content. In three patients of group IV an adenocarcinoma in situ was diagnosed, after 5, 6, and 10 years, respectively. In two patients of group III, a low- and a high-grade dysplasia were observed at 3 and 6 years follow-up, respectively. One patient of group I first acquired a high protein content, then an aneuploid DNA content, and then progressed to adenocarcinoma (12 years). None of the still diploid patients (17 cases) have progressed to dysplasia or cancer compared with 6 of 13 presently aneuploid patients (P < 0.01). In conclusion, DNA/protein FC is a marker of increased malignant potential and thus may be used to detect patients at higher risk in dysplasia-free BE and assist in understanding the various stages of malignant transformation in long-term follow-up studies.

Hyperthermia enhances the response of paclitaxel and radiation in a mouse adenocarcinoma

PURPOSE The aim of our study was to investigate if the efficacy of paclitaxel and paclitaxel-radiation treatments in vivo could be enhanced by hyperthermia. MATERIALS AND METHODS Paclitaxel was administered i.p. in doses from 30 to 60 mg/kg b.w. to (C3D2F1) mice bearing spontaneous mammary carcinoma. Local hyperthermia (41 degrees, 42 degrees, 43 degrees C) was carried out by immersing tumor-bearing legs in a water bath for 1 h. Single X-ray treatments from 10 to 90 Gy were performed. Tumor growth delay (TGD) or tumor control dose (TCD(50), radiation dose needed to induce local tumor control in 50% of irradiated animals) were the endpoints. RESULTS A significant increase of dose-dependent growth delay was observed in paclitaxel and 43 degrees C hyperthermia combined treatments, and a superadditive effect was seen with paclitaxel 45 mg/kg. Combined treatments with hyperthermia at 41 degrees and 42 degrees C were less effective. Administration of paclitaxel 24 h, 4 h, and 15 min before or 15 min and 4 h after hyperthermic treatments produced similar results (TGDs varying from 22.1 to 17 days), and administering paclitaxel 48 h before or 24 h after hyperthermic treatments decreased TGDs (about 10 days). Trimodality treatment (paclitaxel 45 mg/kg, hyperthermia, and X-ray), with a TCD(50) of 14. 1 Gy, in respect to the TCD(50) of 53.1 obtained with X-ray alone, was the most effective. CONCLUSIONS Hyperthermia enhanced the effectiveness of paclitaxel in all the tested protocols. Our results show a superadditive effect of paclitaxel 45 mg/kg combined with a hyperthermic treatment of 1 h at 43 degrees C. Trimodality treatment, evaluated in terms of percentage of cures, shows a very high enhancement ratio.

Flow cytometric DNA ploidy, p53, PCNA, and c-erbB-2 protein expressions as predictors of survival in surgically resected gastric cancer patients†

In order to determine retrospectively the impact of some cytometric and immunohistochemical parameters on the overall survival of gastric cancer patients treated with surgery alone, paraffin-embedded tumor samples from 137 gastric carcinoma patients undergoing curative resection from 1987-1993 were analyzed by flow cytometry (FCM) and immunohistochemistry (p53, c-erbB-2, and PCNA expression). FCM-derived parameters were DNA ploidy and fraction of S-phase cells (SPF). Multiple regression analysis was applied to determine the prognostic significance of the conventional clinicopathologic findings together with the flow cytometric and immunohistochemical parameters on overall survival. When all parameters were entered simultaneously into the Cox regression model, stage and DNA ploidy (DNA index >1.35) clearly emerged as the only independent prognostic factors. When the stages were analysed separately, the independent prognostic factors resulted DNA ploidy in early stages (I-II) and grading in stage IIIA tumors. For stage IIIB tumors, no independent prognostic factor was found. These results indicate that the DNA ploidy pattern is a valuable predictor of survival in curatively resected gastric cancer patients, especially when less advanced tumors are taken into consideration.

Expression and DNA binding activity of the Ku heterodimer in bladder carcinoma

The Ku protein is a tightly associated heterodimer, comprised of 70‐kilodalton (kD) and 86‐kD subunits, that forms the DNA‐dependent protein kinase (DNA‐PK) complex together with the 470‐kD DNA‐PKcs catalytic subunit, and is involved mainly in DNA double‐strand breaks (DSBs) repair. The objective of the current study was to investigate the expression and DNA‐binding activity of the Ku protein in fresh tissues from patients with bladder carcinoma and to compare it with that in nontumor tissues obtained from the same organ. Moreover, the DNA‐binding activity of Ku was assessed after exposure of the tumor cells to 1 or 2 grays (Gy) of X‐rays. Furthermore, the level of phosphorylated Ku was analyzed in both the nuclear and cytoplasmic compartment of normal tissue after exposure to 2 Gy of X‐rays.

POSTOPERATIVE ADJUVANT CHEMORADIATION IN COMPLETELY RESECTED LOCALLY ADVANCED GASTRIC CANCER

BACKGROUND The 5-year survival of patients with completely resected node-positive gastric cancer ranges from 15% to 25%. We explored the feasibility of a chemoradiation regime consisting of concomitant hyperfractionated radiotherapy and 5-fluorouracil protracted venous infusion (5-FU PVI). MATERIALS AND METHODS Forty patients received a total or partial gastrectomy operation and D2 nodal resection for Stage III gastric cancer; they were then irradiated by linac with 6-15-MV photons. The target included the gastric bed, the anastomosis, stumps, and regional nodes. A total dose of 55 Gy was given in 50 fractions using 1.1 Gy b.i.d. All patients received a concomitant 200 mg/m2/day 5-FU PVI. Patients were examined during the follow-up period as programmed. Toxicity was recorded according to RTOG criteria. RESULTS After a median follow-up of 75.6 months (range: 22-136 months), 24 (60%) patients had died, and 16 (40%) were alive and free of disease. The 5-year actuarial incidence of relapse was 39%, 22%, and 2% for distant metastases, out-field peritoneal seeding, and in-field local regional recurrences, respectively. The 5-year actuarial cause-specific survival was 43%. Three patients survived more than 11 years. Acute > or = Grade 3 toxicity consisted of hematologic (22.5%) and gastrointestinal toxicity (nausea and vomiting 22.5%, diarrhea 2.8%, and abdominal pain 2.6%). No late toxicity was observed. CONCLUSION This regime of concomitant 5-FU PVI and hyperfractionated radiotherapy was well tolerated and resulted in successful locoregional control and satisfactory survival.

Enhancement of Radiation Response by Paclitaxel in Mice According to Different Treatment Schedules

PURPOSE The aim of our study was to determine if paclitaxel could be used as a radiosensitizer in vivo. MATERIALS AND METHODS Paclitaxel was tested as a single agent and combined with an X-ray treatment. Paclitaxel was administered i.p. in doses from 30 to 120 mg/kg b.w. to (C3D2F1) mice bearing spontaneous mammary carcinoma. Tumor growth delay (TGD) or tumor control dose (TCD50, radiation dose needed to induce local tumor control in 50% of irradiated animals) and moist desquamation dose (MDD50, radiation dose needed to induce serious moist desquamation in 50% of the non-tumor-bearing feet) were the endpoints. DNA flow cytometric analysis was performed. RESULTS DNA analysis demonstrated a G2/M block of tumor cells and a depletion of cells in S phase, with a maximum at 24 h from paclitaxel administration. Administering paclitaxel, in graded doses, 15 min before a 10-Gy X-ray treatment resulted in a linear regression line, almost parallel to that with paclitaxel alone, with a growth delay of about 6 days. In contrast, varying the X-ray dose with a constant paclitaxel injection (45 mg/kg b.w.) treatment showed some degree of synergism as the linear regression curves diverged. Interval time and sequence between paclitaxel administration and a 10 Gy X-ray treatment did not influence TGD. Protocols with paclitaxel at 30, 45, or 60 mg/kg were combined with radiation treatments at various doses (from 10 to 65 Gy). Values of TCD50 varied from 50.8 Gy for X-ray alone to 31.8 Gy for paclitaxel 60 mg/kg + X-ray. No differences were observed among MDD of different protocols. CONCLUSIONS These results suggest that, under some conditions, paclitaxel combined with radiation can show superadditive effects and this result combined with the lack of severe normal tissue damage indicate that a favorable therapeutic gain can be obtained.

Radioresistance in a tumour cell line correlates with radiation inducible Ku 70/80 end-binding activity.

Purpose: The aims of the present study were to better understand the role of Ku 80, which is involved in double-strand break repair in mammalian cells in the mechanism of radiation resistance and to verify the possibility of increasing cell radiosensitivity by targeted inhibition of Ku autoantigen 80 (Ku 80). Materials and methods: Western blot and electrophoretic mobility shift assay (EMSA) were performed on the human bladder carcinoma cell line RT112 (radioresistant) and on the human colorectal carcinoma cell line SW48 (radiosensitive) to assess the expression levels of DNA-dependent protein kinase (DNA-PK) components and the DNA-binding activity of the Ku 70/80 heterodimer after exposure to radiation, respectively. Ku 80 silencing was carried out with the use of small interfering RNA (siRNA). Results: Greater differences in the DNA-binding activity of Ku 70/80 and Ku 80 phosphorylation level were observed in RT112 as compared to SW48 after X-ray treatment. There is no correlation between Ku expression and DNA-binding activity at lower doses. A significant increase in nuclear Ku 80 expression was observed one hour after the exposure, only at the higher doses, while the DNA-PK catalytic subunits (DNA-PKcs) and Ku 70 levels did not change significantly. Inhibition of Ku 80 expression by siRNA induced radiosensitivity in the RT112 cell line. Conclusions: Our data demonstrate that in a bladder tumour cell line up-regulation of Ku end-binding activity without any marked change in Ku expression underlie radiation resistance.

Greater antitumor efficacy of paclitaxel administered before epirubicin in a mouse mammary carcinoma

Abstract Combined treatment with paclitaxel and anthracyclines is increasingly being tested in clinical practice. Epirubicin is in general administered before paclitaxel. We have investigated, using a murine mammary adenocarcinoma, whether the efficacy and toxicity of this combination is influenced by treatment sequence, different time intervals and dose intensity. The tumor was transplanted into the right hind foot of C3D2F1 female mice. Paclitaxel was administered i.p. in doses ranging from 15 mg/kg to 75 mg/kg and epirubicin (i.p. or i.v.) in doses from 9 mg/kg to 30 mg/kg. The hepatic and peritoneal toxicity observed with epirubicin administration increased in combined treatments (stronger with i.p. than i.v. epirubicin administrations) and was dose-dependent. When paclitaxel and epirubicin were administered simultaneously or paclitaxel was given 24 h before epirubicin, the same tumor growth delays were obtained in all groups. A smaller effect was observed when paclitaxel was administered 24 h after epirubicin. Increasing the epirubicin or paclitaxel dose led to higher tumor growth delays but also an increased toxicity. In conclusion, in this experimental model, the administration of 45 mg/kg paclitaxel before 15 mg/kg epirubicin was very effective and the increased toxicity can be limited by introducing an interval of 24 h between drug administrations. These results should be considered when designing clinical trials.

Accelerated hyperfractionated radiotherapy and concurrent protracted venous infusion chemotherapy in locally advanced head and neck cancer.

Concurrent radiotherapy and chemotherapy result in a significant benefit with respect to induction chemotherapy followed by radiotherapy or radiotherapy alone, although with a significant increase of toxicity. To discover a more tolerated and effective chemoradiation regimen, the feasibility and efficacy of a hyperfractionated accelerated irradiation with concurrent protracted venous infusion chemotherapy was investigated. Sixty-five patients with advanced head and neck cancer underwent a definitive (53 patients) or a postoperative adjuvant (12 patients) chemoradiation treatment. Chemotherapy consisted of an intravenous protracted infusion of 5 and 200 mg/m2/d cisplatin and 5-fluorouracil, respectively. Radiotherapy consisted of a split-course accelerated hyperfractionation of two 150-cGy (split twice a day) or three 100-cGy fractions per day (split three times a day) at more than 6-hour intervals, for 2 weeks followed, after a 1-week interruption, by 2-to-3-week treatment, with the same fractionation schedule, to a total dose of 60 Gy to 69 Gy. Confluent mucositis was tolerable and was the cause of treatment delay of more than 10 days in only 20% of patients. Grade 3 or greater systemic toxicity occurred only in 9 of 65 (14%) patients and was never the cause of drug dose reduction. Complete responses were observed in 69% of patients with gross diseases. At a median follow-up of 43.5 months, 45% of patients were alive and free of disease and 38% died of cancer. The 5-year actuarial local regional failure was 35%. The 5-year actuarial disease-specific survival was 50%. Preservation of larynx function was achieved in 47% of living patients and in 74% of all patients, with advanced tumors of the laryngopharynx. The long-term results of this study suggest that this chemoradiation regimen has the potential of achieving a significant improvement over standard therapy while avoiding significant toxicity.