Antitumor activity of Ru(III) complexes carrying beta-diketonato ligands in vitro and in vivo.

PURPOSE: To investigate the antitumor activity of two newly synthesized ruthenium(III) [Ru(III)] compounds carrying bidentate ligands: (acac)-acetylacetonate, [Ru(acac)3), and (tfac)-trifluoroacetylacetonate [Ru(tfac)3]. MATERIALS AND METHODS: The activity of ruthenium(III) analogues was evaluated on HeLa, B16, and Femx cell lines for cytotoxicity in vitro using MTT assay, and inhibition on tumor invading ability in vitro using cell migration and invasion assays, whereas inhibition of tumor growth in vivo was estimated on advanced B16 murine melanoma model. Both compounds were also investigated in combinations with cisplatin, oxaliplatin, or poly ADP-ribose polymerase- 1 (PARP-1) inhibitor, in order to determine the pattern of mutual interactions. RESULTS: Applied as single drugs, Ru(tfac)3 showed high cytotoxic activity against HeLa and Femx cell lines, while Ru(acac)3 did not reach the IC50 on any of the cell lines tested. In combinations, Ru(acac)3 with cisplatin gained synergistic interaction, antagonistic with oxaliplatin, and of different kind with (PARP-1) inhibitor in concentration-and cell line-dependent manner. Ru(acac)3 exhibited inhibition of HeLa cell migration and gelatinolytic activity of MMP-2 and MMP-9. Ru(tfac)3 complexes did not induce significant reduction of melanoma growth in vivo, whereas Ru(acac)3 did, but the latter failed to contribute in lifespan improvement. CONCLUSION: The investigated ruthenium complexes showed different levels of antitumor activity in vitro and in vivo, implicating on different mechanisms of their action as well as diverse perspectives in cancer treatment.

TP53 mutations in breast cancer: association with ductal histology and early relapse of disease.

PURPOSE: This study aimed to investigate the incidence of core domain TP53 mutations in Serbian breast cancer patients in view of their possible correlation with prognostic parameters, tumor characteristics and clinical disease course. METHODS: 145 breast cancer patients were included. Data on clinical disease course were available for 100 patients including 30 node-negative and 70 node-positive patients. After surgery, node-positive patients underwent adjuvant chemotherapy, mostly CMF. TP53 mutations were detected by PCR-SSCP. RESULTS: 31 mutations were found in 27/145 patients including 4/59 node-negative patients and 23/83 node-positive patients (4 double mutations). 26/31 TP53 mutations were found in patients with invasive ductal carcinoma and only 2 in patients with invasive lobular carcinoma. The presence of TP53 mutations was correlated with clinical disease course in premenopausal node-positive patients (n=70). 11/20 patients with TP53 mutations relapsed. Within the first 24 months of follow-up, significantly shorter disease-free intervals were observed in TP53-mutated patients. CONCLUSIONS: TP53 mutations correlated only with nodal status and ductal histology. The significance of the predominant distribution of TP53 mutations in tumors with a ductal histology for the aggressive behavior of these tumors has yet to be proved, since the favorable biological features of tumors with a lobular histology do not result in a better prognosis. Early relapse in mutated-TP53 carriers may support data on its predictive value with respect to adjuvant CMF.

Analysis of T-cell clonality pattern in tumor samples of breast cancer patients.

PURPOSE AND METHODS: A large body of experimental evidence has confirmed that different tumors, including breast carcinomas, can stimulate specific T-cell-mediated immune responses. In this study we have analyzed patterns of T-cell clonality in tumor samples of 54 breast cancer patients classified as lymph node negative, N0 (n=16), or lymph node positive, N+ (n=38). The clonality of T-cells was analyzed by the PCR-PAGE method. RESULTS: Monoclonal/oligoclonal (M/O) T-cell populations were found in 15 breast cancer patients, nine N+ and six N0. In all analyzed groups (N+ + N0, N+, N0) the incidence of relapse was not significantly different between patients with M/O and patients with polyclonal T-cells. Comparison of disease-free interval (DFI) between patients divided according to the presence of TCRgamma monoclonality/oligoclonality showed a marginally significant difference only in the group of N+ patients within the first 24 months of follow-up. Patients with a M/O T-cell population had a shorter DFI than patients with a polyclonal T-cell population. This difference was not observed when the complete follow-up period was considered in the same group of patients. Furthermore, there was no significant difference in overall survival (OS) between patients with M/O and patients with polyclonal T-cells. CONCLUSION: Our results imply that tumor infiltrating T-cells are usually polyclonal. The pattern of T-cell clonality does not correlate with the incidence of relapse and the duration of DFI and OS in the analyzed groups of breast cancer patients, excluding N+ patients with M/O T-cells who had a shorter DFI in the first 24 months of follow-up. This observation suggests that polyclonal T-cell populations may provide a broader spectrum of T-cell-mediated antitumor response.

The evaluation of cytotoxic activity of planar pentadentate ligand 2',2"'-(2,6-pyridindiyldiethylidyne) dioxamohydrazide dihydrate (H2l x 2H2O) and its metal coordination complexes; pitfalls in the use of the MTT-assay.

In this study we have investigated, for the first time to our knowledge, the antineoplastic activity of a planar pentadentate ligand (H2L.2H2O = 2', 2'''-(2,6-pyridindiyldiethylidyne)dioxamohydrazide dihydrate) and some of its metal coordination complexes [Cu(L)(H2O)].H2O, [Cu(HL)(H2O)]Cl04, [Co(L)(H20)2] 6H20, [Co(H2L)(H2O)(MeOH)](ClO4)2 and [Fe(L)(H2O)2]ClO4-3H2O, as well as of inorganic salts CuCl2 2H20, CoCl2 6H2O and FeCl3.6H2O of corresponding metal ions. The antiproliferative activity of these compounds was examined in a human melanoma cell line FemX with exposure time of 48 hours by performing two cytotoxicity tests: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and sulforhodamine B (SRB) assay. Among these substances, the ligand H2L.2H2O expressed the greatest antineoplastic activity IC50 = 45.40 microM, while the IC50 of others could not be determined by SRB assay in the examined range of concentrations due to their low activity. FeCl3.6H2O showed stimulatory activity. We have found remarkable discrepancies between the results obtained by MTT assay and SRB assay that influence IC50 value as well as other measures of cytotoxicity, which led to the conlusion of uncertainty of using the MTT assay in evaluation of antineoplastic activity of organometalic complexes and inorganic metal salts.

Analysis of T-cell clonality pattern in tumor samples of breast cancer patients.

PURPOSE AND METHODS: A large body of experimental evidence has confirmed that different tumors, including breast carcinomas, can stimulate specific T-cell-mediated immune responses. In this study we have analyzed patterns of T-cell clonality in tumor samples of 54 breast cancer patients classified as lymph node negative, N0 (n=16), or lymph node positive, N+ (n=38). The clonality of T-cells was analyzed by the PCR-PAGE method. RESULTS: Monoclonal/oligoclonal (M/O) T-cell populations were found in 15 breast cancer patients, nine N+ and six N0. In all analyzed groups (N+ + N0, N+, N0) the incidence of relapse was not significantly different between patients with M/O and patients with polyclonal T-cells. Comparison of disease-free interval (DFI) between patients divided according to the presence of TCRg monoclonality/oligoclonality showed a marginally significant difference only in the group of N+ patients within the first 24 months of follow-up. Patients with a M/O T-cell population had a shorter DFI than patients with a polyclonal T-cell population. This difference was not observed when the complete follow-up period was considered in the same group of patients. Furthermore, there was no significant difference in overall survival (OS) between patients with M/O and patients with polyclonal T-cells. CONCLUSION: Our results imply that tumor infiltrating T-cells are usually polyclonal. The pattern of T-cell clonality does not correlate with the incidence of relapse and the duration of DFI and OS in the analyzed groups of breast cancer patients, excluding N+ patients with M/O T-cells who had a shorter DFI in the first 24 months of follow-up. This observation suggests that polyclonal T-cell populations may provide a broader spectrum of T-cell-mediated antitumor response. (Int J Biol Markers 2005; 20: 177-83).

High efficacy of a single oral dose of ondansetron 8 mg versus a metoclopramide regimen in the prevention of acute emesis induced by fluorouracil, doxorubicin and cyclophosphamide (FAC) chemotherapy for breast cancer.

The aim of our single-center, prospective, randomized, open study was to evaluate the antiemetic efficacy and tolerability of a regimen based on a single oral dose of ondansetron 8 mg in comparison with a metoclopramide-based regimen, for prevention of acute FAC (fluorouracil, doxorubicin and cyclophosphamide) chemotherapy-induced emesis. A total of 149 chemotherapy-naive, female outpatients, under 50 years of age and with no history of alcohol consumption, scheduled to receive their first cycle of FAC chemotherapy, were included. The patients received either oral ondansetron (8 mg) or metoclopramide (1.5 mg/kg, i.v.), both combined with dexamethasone (16 mg, i.v.) and alprazolam (0.5 mg t.i.d. orally). No antiemetic prophylaxis was given for delayed emesis. Complete control of acute vomiting was obtained in 69/74 (93%) of patients receiving ondansetron, and in 49/75 (65%) of those receiving metoclopramide (p=0.00003). Complete control of acute nausea was obtained in 58% of patients receiving ondansetron and in 36% of those receiving metoclopramide (p=0.007). Complete prevention of delayed vomiting/nausea was achieved in 73%/20% and 60%/16% of patients, respectively. Sedation was more frequent in the metoclopramide arm (p=0.04). As far as we know this is the first study that supports the efficacy of a regimen based on a single oral dose of ondansetron 8 mg in the prevention of acute FAC chemotherapy-induced emesis. The ondansetron regimen was highly effective in female patients and was superior to the metoclopramide based regimen.

Single 8 mg dose of oral ondansetron failed to prevent FAC chemotherapy-induced acute nausea and vomiting.

The aim of this open, nonrandomized, monocentric study was to evaluate the efficacy of a single daily dose of 8 mg oral ondansetron in the prophylaxis of acute nausea and vomiting in chemotherapy-naive breast cancer patients receiving their first cycle of chemotherapy with 5-fluorouracil, doxorubicin and cyclophosphamide (FAC). Forty-five female patients were recruited, median age 42 years. The number of emetic episodes and the grade of nausea were recorded. 51% of patients achieved complete, and 9% major control of acute emesis. 33% of patients experienced no acute nausea, and in 18% nausea was mild. Complete protection from nausea and vomiting (complete prophylaxis) was obtained in 12/45 (27%) of patients. Treatment success (no vomiting with no more than mild nausea) was achieved in 18/45 (40%) of patients. We conclude that the efficacy of a single dose of 8 mg oral ondansetron in controlling acute nausea and vomiting induced by FAC chemotherapy is not high enough to justify its use as a sole antiemetic agent in outpatients.

Daily oral etoposide in metastatic breast cancer.

Etoposide, administered i.v. or orally, as a single agent, in 1- to 5-day courses, was found to be minimally effective in pretreated advanced breast cancer patients. Clinical data suggested an effectiveness of a chronic low-dose oral etoposide schedule, in refractory and those malignancies otherwise unresponsive to the drug. Therefore, the aim of our open-labeled, non-randomized, phase II clinical study was to investigate the efficacy and toxicity of chronic daily etoposide (50 mg/m2 daily, for 21 consecutive days, every 28 days) as a first-line chemotherapy for metastatic breast cancer. Twenty-one advanced breast cancer patients, with or without previous adjuvant CMF chemotherapy, were included. One complete (CR) and five partial remissions (PR) were obtained in 18 patients evaluable for response. Disease stabilization was obtained in 10 patients (55%), while two patients (11%) failed to respond. Grade 3-4 hematological toxicity developed in seven out of 21 patients evaluable for toxicity or in 15 out of 96 cycles. Nonhematological toxicity was moderate. Our results showed the efficacy and relative low toxicity of a chronic oral etoposide regimen in advanced breast cancer patients. Adjuvant CMF chemotherapy did not influence the therapeutic response. Previous irradiation of the breast tended to increase the etoposide hematological toxicity.

Therapeutic and endocrine effects of Decapeptyl, synthetic LH-RH agonistic analogue in premenopausal women with metastatic breast cancer. A pilot phase II study.

Twelve premenopausal patients with advanced breast cancer were entered into pilot phase II study to assess efficacy, toxicity and influence of the synthetic LH-RH agonistic analogue D-Trp6-LH-RH (Decapeptyl) on the patients' hormonal status. The patients, aged 33-50, with newly diagnosed stage IV or recurrent breast cancer were not previously treated by any kind of endocrine therapy. Steroid receptor status was known in 9 patients. Decapeptyl was applied monthly at a dose of 3.75 mg i.m. until progression. The therapeutic response was evaluated in 11/12 patients. Partial remission was achieved in 5, stabilization in 3, and 3 consecutive patients failed to respond. The best therapeutic response was obtained in patients with pleuropulmonal and soft-tissue involvement, aged 41-45, including those with incomplete ovarian suppression, and regardless of steroid receptor status. The mean serum gonadotropins and estradiol levels were suppressed. The treatment was free of any side effects, except hot flushes in 7 patients.

The binding of bombesin and somatostatin and their analogs to human colon cancers.

Specific receptors for bombesin/gastrin-releasing peptide, somatostatin, and EGF were investigated in 15 human colon cancer specimens. Eight of 15 clinical specimens (15%) of colon cancer showed the presence of somatostatin receptors. Octapeptide somatostatin analogs, RC-160 and RC-121, showed 10 times higher binding affinity for somatostatin receptors on colon cancer membranes than somatostatin. Analysis of 125I-Tyr4-bombesin binding data revealed the presence of specific binding sites in six (40%) specimens of human colon cancer. Scatchard analysis of 125I-labeled bombesin indicated a single class of receptors in three specimens with an apparent Kd value of 2.5 nM and two classes of receptors with high (Kd = 0.4 +/- 0.2 nM) and low affinity (Kd = 1.6 +/- 0.4 microM) in three other specimens. The 125I-Tyr4-bombesin binding capacities in the colon cancers for high affinity binding sites were from 6 to 228 fmol/mg protein and for low affinity binding sites 76 +/- 15 pmol/mg protein. None of the membrane preparations made from normal colonic mucosa specimens showed specific binding for 125I-Tyr4-bombesin. Five pseudononapeptide (psi 13-14) bombesin (6-14) antagonists, with different modifications at Positions 6 and 14, synthesized in our laboratory, inhibited the binding of 125I-Tyr4-bombesin in nanomolar concentrations. No correlation was found between the degree of differentiation and the presence of binding sites for somatostatin or bombesin. Specific binding of EGF was detected in 80% of colon cancer specimens. EGF binding capacity in colon cancer membranes was on average twice as high as in normal colon mucosa (50 +/- 21 vs 28 +/- 14 fmol/mg protein, respectively). Specific binding sites for somatostatin and EGF, but not bombesin, were also demonstrated in human colon cancer cell line HT-29. In HCT-116 colon cancer line only EGF receptors were found. These receptor findings and our in vivo studies on inhibition of colon cancer growth support the merit of continued evaluation of somatostatin analogs and bombesin/gastrin-releasing peptide antagonists in the management of colonic carcinoma.