Difference in Ki67 and thymidylate synthase expression in primary tumour compared with metastatic nodes in breast cancer patients.

Breast cancer is a heterogeneous disease, so therapeutic predictive biological markers need to be identified. To date an accurate evaluation of predictive markers is mainly done at the primary site; however, the main goal of adjuvant therapy for breast cancer is the control of micrometastases. The aim of this study is to assess as therapeutic and/or prognostic marker, the proliferation status of primary tumors and involved nodes as measured by Ki67 and thymidylate synthase (TS) expression, in 30 breast cancer node positive patients. TS is the main target of 5-fluorouracil (5-FU) activity, and its overexpression is one of the mechanisms of 5-FU drug resistance; however, in some studies its absence is responsible for a worse response to 5-FU. Our results show that malignant cells of involved nodes were in a post mitotic phase of the cell cycle, and show a low proliferation index and TS expression, while the primary tumours and controls, were strongly positive. On these basis we can hypothesize that these cells could be less sensitive to 5-FU. Further studies are necessary to identify other mechanisms responsible for their metastasing capability and/or for their aggressiveness.

The CD95/CD95 ligand system is not the major effector in anticancer drug-mediated apoptosis.

Many anticancer drugs are able to induce apoptosis in tumor cells but the mechanisms underlying this phenomenon are poorly understood. Some authors reported that the p53 tumor suppressor gene may be responsible for drug-induced apoptosis; however, chemotherapy-induced apoptosis can also be observed in p53 negative cells. Recently, doxorubicin (DXR) was reported to induce CD95L expression to mediate apoptosis through the CD95/CD95L system. Thus, an impairment of such a system may be involved in drug resistance. We evaluated the in vitro antitumor activity of several cytotoxic drugs on two human p53-negative T-cell lymphoma cell lines, the HUT78-B1 CD95L-resistant cell line and the HUT78 parental CD95L-sensitive cell line. We demostrated by Western blotting assay that DXR and etoposide (VP-16) were able to induce CD95L expression after 4 h of treatment. In contrast, they were unable to induce the expression of p53. DXR, at concentrations ranging from 0.001 - 1 microg/ml, and VP16, at concentrations ranging from 0.05 - 1 microg/ml, were equally cytotoxic and induced apoptosis in both cell lines as assessed by fluorescence microscopy and flow cytometry analyses. Although we observed a slightly reduced percentage of apoptotic cells in HUT78B1 when compared with the parental HUT78 cells after few hours of drug exposure, this difference was no longer evident at 48 or 72 h. Similarly, the exposure of HUT78 cells to a CD95-blocking antibody partially reduced early apoptosis (24 h) without affecting the long-term effects of the drugs including cytotoxicity. Furthermore, as observed with DXR and VP-16, both the CD95L-sensitive and the CD95L-resistant cell lines resulted equally sensitive to the cytotoxic effects of a number of different cytotoxic drugs (vincristine, camptothecin, 5-fluorouracil and methotrexate). The treatment with the Caspase-3 tetrapeptide aldehyde inhibitor, Ac-DEVD-CHO, did not affect the DXR-induced apoptosis whereas it only modestly inhibited apoptosis and cytotoxicity of VP-16, while Z-VAD.FMK, a Caspase inhibitor that prevents the processing of Caspase-3 to its active form, was able to block DXR-induced apoptosis at 24 h but not at 48 h. Thus, our results do not confirm a crucial role for the CD95/CD95L system in drug-induced apoptosis and suggest the involvement of alternative p53-independent pathways at least in this experimental model system.

Clinical relevance of thymidylate synthase expression in the signet ring cell histotype component of colorectal carcinoma.

Thymidylate Synthase (TS) is the key enzyme for DNA synthesis pathways and is inhibited by 5-fluorouracil (5FU). The aim of this work was to study TS expression and the proliferation rate in the different histological types of colorectal carcinoma (CRC). 50 patients with CRC were included in this study and evaluated immunohistochemically using the monoclonal antibodies, TS106 and Ki67. 20 tumours were of the intestinal type, 15 cases were signet ring cell carcinoma (SRCCs) and 15 cases were "mixed-type", with at least two different histological components. Intestinal and mucinous histotypes were positive for TS and Ki67, while "signet ring cell" samples were negative or showed only weak and focal positivity for both the TS and Ki67 antibodies. Our results show that signet ring cells (that are also often present in intestinal and mucinous carcinomas), are in the post-mitotic phase of the cell cycle and show a low proliferation index and TS expression. As TS is the key enzyme for DNA synthesis pathways and is inhibited by 5-fluorouracil (5FU), we can hypothesise that TS expression levels in the different histotypes of CRC could affect the potential responsiveness of these tumours to fluoropyrimidine chemotherapy, with a low efficacy being expected in signet ring cell areas.

Subcutaneous recombinant-human-erythropoietin prevents chemotherapy-related anemia in patients with advanced cancer.

Nineteen patients with advanced cancer were randomly allocated to receive: (i) rhEpo 150 UI/kg subcutanously three times/week starting 24 hours after the completion of cisplatin- or carboplatin-based chemotherapy; or (ii) normal saline. There were 17 patients with advanced head and neck carcinoma and 2 patients with small cell lung cancer. Patients were monitored for hemoglobin level, hematocrit, WBC, PLT and reticulocytes. Patients who received rhEpo overall showed a 7.2 +/- 6.3% mean increase in Hb level over their pretreatment values, while control patients had a 26.4 +/- 12% decrease. This difference was statistically significant (p<0.001). No patients in the rhEpo group required transfusion, while 4 patients in the control group received packed red cell transfusion. No significant side-effects attributable to rhEpo were recorded, but 1 patient showed a transitory increase in PLT count. In conclusion, subcutaneous rhEpo may be safely administered to patients with advanced cancer and effectively prevents cisplatin- or carboplatin-related anemia.

Cis-diamminodichloroplatinum plus a 5-day continuous infusion of 5-fluorouracil in the treatment of locally recurrent and metastatic head and neck cancer patients.

A group of 23 consecutive patients with biopsy-proven advanced or metastatic head and neck cancer were treated with cisplatinum, 100 mg/m2 i.v., on day 1 plus 5-fluorouracil, 1000 mg/m2, in continuous infusion for 5 days. Most patients (87%) had recurrent or metastatic cancer and were previously treated (78%). Out of 21 evaluable patients we obtained a 42% overall response rate (complete + partial responses) with a mean duration of more than 8 months and a 14% minimal response rate. A stabilization of disease was achieved in 28% of cases, while 14% of patients progressed. This response rate, as well as the duration of response, seems to be similar to those obtained in other series comprising previously treated patients with advanced or metastatic head and neck carcinoma. The toxicity was generally acceptable, with few cases of grade 3 (WHO criteria) toxicity. However most patients required hospitalization because of the length of treatment. In conclusion the response rate and the duration of responses obtained with cisplatinum plus a 5-day infusion of 5-FU in advanced or metastatic pretreated patients is, at present, unsatisfactory, even if the impact on survival is still not entirely clear.

Combination chemotherapy with mitomycin C, vindesine and melphalan for refractory metastatic breast cancer.

A combination of mitomycin C, vindesine and melphalan was administered to 33 patients with heavily pretreated refractory breast cancer. The overall response rate was 27% with a mean duration of more than 10.2 months. A stabilization with a mean duration of 5.1 months was seen in 56% of cases, while 20% of patients progressed. Gastrointestinal toxicity, mostly grade 1 or 2 nausea/vomiting was seen in 85% of cases, grade 1 or 2 leukopenia in 60% of patients, and grade 1 or 2 thrombocytopenia in 42%. Considering the good compliance of this regimen and the poor prognosis of patients with refractory advanced breast cancer, this combination can be useful as a palliative treatment of breast carcinoma.

High-dose folinic acid and 5-fluorouracil plus cisplatin on a weekly schedule in the treatment of advanced cancer of the head and neck.

A group of 60 patients with advanced head/neck cancer were treated with high-dose folinic acid (500 mg/m-2/week-1) plus 5-fluorouracil (400 mg/m-2/week-1 on day 1, and cisplatin (20 mg/m-2/week-1) 24 h after folinic acid infusion was completed. Out of 55 evaluable patients, 10 patients (18%) experienced a complete response with a mean duration of 11.4+ months, 25 patients had a partial response (45%) of 6.7+ months, 6 patients (11%) showed a stabilization of 4.8+ months, and 14 (25%) progressed. The overall response rate was 63.6% (95% confidence limits 56.5%-69.5%). Patients pretreated with radiotherapy had a 67% overall response rate, while those pretreated with chemotherapy showed a 54% overall response rate. All patients with cancer of the oropharynx had a major response, while patients with cancer of the oral cavity had the lowest response rate. The mean survival of patients who attained a complete response was 14.5+ months. Partial responders had a mean survival of 10.6+ months, while patients who progresses survived a mean of 3.6+ months. The treatment has been very well tolerated with few cases of grade 3 gastrointestinal toxicity. Grade 1-2 leukopenia was recorded in 64% of cases, grade 1-2 nausea/vomiting in 85%. In one case therapy was stopped because of persistent diarrhoea.

5-Fluorouracil plus interferon alpha-2a compared to 5-fluorouracil alone in the treatment of advanced colon carcinoma: a multicentric randomized study.

Biochemical modulation is one of the most interesting fields in cancer chemotherapy. Interferon-alpha (IFNalpha) is a cytokine that is able to influence the pharmacodynamics of 5-fluorouracil (5FU) through a number of mechanisms. With the aim of confirming some data emerging from the literature, we initiated a multicentric randomized study comparing the combination of 5FU and IFNalpha-2a with 5FU alone in the treatment of advanced or metastatic colon cancer. A group of 205 colon cancer patients (104 in the 5FU arm and 101 in the 5FU + IFNapha-2a arm) were included in the final intention-to-treat analysis. Rectal cancers were not considered eligible. All patients had measurable disease, were aged 75 years or less, had a Karnofsky index of at least 60 and had good bone marrow, renal, liver and cardiac functions. No previous chemo-immunotherapy was allowed. The treatment was 750 mg/m2 5FU (4 h i.v. infusion) on days 1 5 and then i.v. bolus weekly, starting from day 12, with or without IFNalpha-2a given s.c. three times weekly (starting dose 3 x 10(6) IU rising to 9 x 10(6) IU, if tolerated). Patients were treated until progression or, if responsive, for a maximum of 48 weeks and then observed for a period of 2 years. The primary end-point of the study was objective clinical response (OR); secondary parameters were time to progression, overall survival, and time to death after progression. WHO criteria were used for both clinical response and toxicity measurements. Dose reduction was planned a priori in the event of significant toxicity due to 5FU, IFNalpha-2a or both. Association between primary and secondary end-points and treatment was studied by univariate and multivariate analysis. Altogether, 47 patients achieved a documented response. A 25% OR was observed in the combination arm while a 21% OR was seen in the 5FU arm; this difference is not statistically significant (P = 0.6). Patients with a small tumour burden (below 5 cm2) showed a higher probability of response in both arms. Patients in the experimental arm had a higher but not statistically significant cumulative progression-free probability. Median survival was 47.1 weeks overall, while it was 43.7 and 48.5 weeks in the control and experimental arms, respectively. The combination was clearly more toxic than 5FU alone, leukopenia being the most frequent side-effect in the experimental arm and nausea and vomiting in the control arm. In conclusion these results are quite disappointing and 5FU + IFNalpha-2a can not be considered a standard treatment for advanced colon cancer.

Lysosomal alterations in heart and liver of mice treated with doxorubicin.

This study was carried out to evaluate the influence of long-term treatment with doxorubicin (DXR) (4 mg/kg IV for 5 weeks) on heart and liver lysosomes of mice. We evaluated the variations in both total and "sedimentable" enzyme activity of cathepsin D, which is the major endopeptidase of myocites and probably involved in physiologic and pathologic degradation of actomyosin and mitochondria, and that of acid phosphatase, which is more prominent in interstitial cells. Our results show that marked changes occur in both total and sedimentable enzyme activity of cathepsin D in the heart of treated animals and to a lesser extent in the liver. In contrast, no modification of either total or sedimentable acid phosphatase was seen in either organ. The effects we observed are much more marked for cardiac cathepsin D; this is in good agreement with the cardiac specificity of DXR-induced cardiotoxicity with long-term administration and suggests that lysosomes could play a role in the pathogenesis of this phenomenon.

A cisplatin-based regimen as a salvage treatment for metastatic breast carcinoma.

The role of chemotherapy in refractory metastatic breast cancer is still debated. We employed a schedule of cisplatin, mitomycin and vindesine in twenty-one anthracycline- or anthraquinone-pretreated breast cancer patients. The most relevant characteristics of our group were a good performance status (mean Karnofsky index 84) and a high percentage of bone disease (71%). Out of 20 evaluable patients, 4 (20%) achieved a partial response with a median duration of 3.7 months. Median survival was 12.5 months. Severe gastrointestinal toxicity was reported in 66% of patients and G3 alopecia was seen in 24%. Other side effects, including hematological, were negligible. On the basis of the low response rate and poor tolerability we do not reccommend this combination as salvage treatment in metastatic breast cancer. The use of cisplatin-based regimens in untreated patients waits further investigation.

A short-term infusion regimen of Cisplatin, 5-Fluorouracil and L-folinic Acid in advanced head and neck-carcinoma.

Treatment of advanced head and neck cancer is still a matter of controversy. Although current chemotherapy regimens are able to induce high response rates, they have not shown improved survival. We employed a combination of cisplatin (CDDP), 5-fluorouracil (5FU) and 1-folinic acid (1-FA) in a 6-hour infusion schedule easy to administer on an outpatient basis. 49 patients have been included to date. The treatment plan consists of 5-FU (375 mg/m(2)) plus 1-FA (100 mg/m(2)) in a 4-hour i.v. infusion followed by a 2-hour i.v. administration of CDDP (20 mg/m(2)). This therapy was repeated for five consecutive days and recycled every 3-4 weeks. Out of 46 evaluable patients there were 6 complete responses (CR) and 23 partial responses (PR) for an overall response rate of 63%. Overall survival was 10.2 months (mean). Untreated patients had a higher probability of response as well as patients with naso-oropharyngeal primary tumor. Toxicity was generally mild with leukopenia, anemia and vomiting being the most frequent side effects. In conclusion, this combination appears well tolerated and active in the palliation of advanced head and neck cancer. However we think that increasing dose intensity of standard regimens and experimental new therapeutic approaches are needed to improve the clinical outcome of this disease.

The in vitro effect of recombinant erythropoietin on cisdiamminodichloroplatinum-induced inhibition of murine erythroid stem cells.

An in vitro study was carried out to evaluate the possible protective effect of recombinant human erythropoietin (rhEpo) on cisplatin (CDDP)-induced inhibition of erythroid colony growth. CDDP at the dose of 0.4 mg/ml caused a 72-75% inhibition of erythroid stem cell growth in plasma clots. In the short-term assay rhEpo was not able to protect normal murine erythroid stem cells from the inhibitory effect of CDDP at any of the tested concentrations. In long-term bone marrow cultures, although the kinetics of cellular populations in suspensions and of erythroid stem cells were similar in both controls and CDDP-treated cultures, both cellularity and erythroid stem cells levels were much lower in CDDP-treated flasks than in control ones regardless of the addition of rhEpo. These results indicate that rhEpo is not able to prevent of ameliorate erythroid stem cell inhibition due to a possible toxic effect of CDDP, at least in vitro.

Cathepsin D in the malignant progression of neoplastic diseases (review).

Recent studies suggest that aspartic proteinase Cathepsin D may be implicated in the process of tumor invasion and metastasis. In fact several in vitro observations showed that this proteinase may facilitate the spread of neoplastic cells through different mechanisms related to its proteolytic activity, by acting at different levels of the metastatic cascade. Cathepsin D may promote tumor cell proliferation by acting as an autocrine mitogen through the activation of latent forms of growth factors or by interacting with growth factor receptors. The enzyme was also shown to be able to degrade in vitro extracellular matrix and to activate latent precursors forms of other proteinases involved in the invasive steps of the metastatic process. Although unequivocal proof of its active role in promoting these processes also in vivo has not been obtained so far, recent clinical observations which showed a positive correlation between levels of expression of Cathepsin D activity and malignant progression of some human neoplasms further support this hypothesis. These findings warrant extensive experimental and clinical studies to better assess the pathophysiological role of this acid proteinase in the spread of neoplastic diseases and suggest new and more selective therapeutic approaches to the treatment of human neoplasms.

Thymidylate synthase gene promoter polymorphisms are associated with TSmRNA expressions but not with microsatellite instability in colorectal cancer.

BACKGROUND: Microsatellite instability (MSI) is a biological characteristic of most tumours, being involved in 85% of hereditary non-polyposis colorectal cancer (HNPCC). It also occurs in 10-15% of sporadic colorectal cancers (CRC). HNPCC appears to be caused by germline mutations in mismatch repair (MMR) genes, which are responsible for repairing single base-pair mismatches. MSI is also associated with a better response of CRC to adjuvant chemotherapy with fluoropyrimidines. We investigated any relationship between the MSI status and the TSmRNA expression, the polymorphisms of 5-Fluorouracil (5-FU cellular target, the enzyme thymidylate synthase (TS) and TS expression evaluated by means of immunohistochemistry. MATERIALS AND METHODS: A series of 80 colorectal cancers was evaluated for MSI and polymorphisms in the 3'UTR and the 5'UTR of the TS gene by a PCR assay. TSmRNA was quantified by real-time PCR and the TS expression by immunohistochemical assay. RESULTS: There was no significant association between the polymorphisms in the TS gene and the MSI or between the TSmRNA expression and the MSI status. CRC with a 3R/3R or 2R/3R genotype showed a significantly higher TSmRNA expression than those with the 2R/2R genotype (p = 0.001 and p = 0.028, respectively). Another significant association was found between the TSmRNA expression and the TS immunohistochemical determination (p = < 0.05). No association was found between the polymorphism of the 3'UTR and the TSmRNA expression. CONCLUSION: Our data show that there is no association between MSI status and the polymorphisms in the 3' and 5' UTRs and the TS expression. Tumour samples displaying the 3R/3R or 2R/3R genotype of TS have higher TSmRNA levels than the 2R/2R genotype. Polymorphic variant of the 3'UTR does not influence the TSmRNA level. We found a relationship between the TSmRNA expression, evaluated by real-time PCR, and with the TS level determined by immunohistochemical assay. Thus, genotyping of the 5'UTR and quantification of the TSmRNA expression in human CRC could be considered as predictors for response to SFU-based chemotherapy. The evaluation of the TS expression by means of immunohistochemistry assay remains a safe and reliable assay in CRC.

Thymidylate synthase level and DNA-ploidy pattern as possible prognostic factors in human colorectal cancer: a preliminary study.

5-Fluorouracil is the drug chosen for the treatment of patients with advanced colorectal carcinoma; its major site of action is thymidylate synthase (TS), resulting in pronounced and prolonged inhibition of DNA synthesis. The aim of this study was to evaluate the possibility of considering TS level in human colorectal carcinomas of previously untreated patients (pts) as a prognostic factor. Our data demonstrate that there is no association with age, sex, tumor site and tumor size; however, there is a relationship between TS levels and staging: in fact, the TS values are higher (P < 0.05) in Dukes-A tumors than in the others. A significant association was also found between the TS levels and survival parameters: in fact, pts with longer disease-free and overall survivals had a significantly increased TS level compared to pts with a poorer outcome (P < 0.05). Moreover, pts with DNA-aneuploid tumors had lower TS level (median = 0.044 pmol/mg protein) than diploid pts who had higher TS level (median = 0.093 pmol/mg protein); however the difference is not significant. Our result are based on preliminary data; however, they seem to support the hypothesis that a high TS level is a favourable prognostic factor in human colorectal carcinoma.

Lacidipine and josamycin: two new multidrug resistance modulators.

In this paper we report the results obtained treating a multidrug resistant (MDR) murine erythroleukemia cell line with daunomycin (DNM) in association with two new modulators characterized by a favourable therapeutic index, lacidipine (LCD), a dihydropyridine calcium antagonist, and josamycin (JSM), a macrolide antibiotic. LCD and JSM exhibited a greater MDR reversal activity than verapamil (VRP) and erythromycin (ERY) respectively. The accumulation of DNM in the DRTL cells exposed to modulators was similar to that of the parental cell line FLC. In the case of LCD, it was possible to ascertain that at a very low concentration this molecule can circumvent MDR without modifying DNM accumulation, suggesting that multiple different determinants may be responsible for MDR other than P-170 in this cell line.

Failure of detection of the tyrosine to histidine substitution at the residue 33 of thymidylate synthase in human colorectal cancer. A preliminary study.

Structural changes in the macromolecular targets of pharmacological agents can result in alterations in the efficacy of these agents. In previous studies Berger et al. (1) identified a variant structural form of thymidylate synthase (TS) that is associated with relative resistance to 5-fluoro-2'-deoxyuridine, in a human colonic tumor cell line. They observed that expression of the variant TS, which differs from the normal form by a tyrosine to histidine substitution at residue 33, confers a 4-fold level of drug resistance in mammalian cells, as well as in bacteria. Now we report on the use of RT-PCR techniques to see if that variant TS form could be present in human samples from patients who underwent surgery for primary colorectal cancer and been previously untreated and to try to find relationships between that hypothetical variant TS form and the 5-Fluorouracil treatment. The possible role of Tyr-33 in 5-fluoropyrimidine-mediated inhibition of TS is discussed.

The role of thymidylate synthase levels in the prognosis and the treatment of patients with colorectal cancer.

Inhibition of Thymidylate Synthase (TS) by the 5-Fluorouracil (5Fu) active metabolite Fluoro-deoxy-uridine-monophosphate (FdUMP) is considered to be the main mechanism of action of 5Fu. TS level from tumors and normal mucosa of 62 untreated patients who underwent surgery for primary colorectal adenocarcinoma was performed. The aim of this study was to evaluate the possibility of considering the TS level as a prognostic factor of the disease. A large variation in the level of the enzyme was found among tumors. Our data demonstrate that there is no association with age, sex, and tumor size; however there are significant relationships between TS levels and staging and histological grading. In fact the TS values are higher in Dukes' A and in G1 than in Dukes' D and G3 tumors (p < 0.05). Another significant association has been found between the TS level and tumor site: pts with right colon neoplasias had higher TS levels than pts with left and rectum ones. An interesting trend was found between the TS levels and survival parameters. Pts who had lower TS levels had a significantly increased risk of death (p < 0.05) over pts with a higher outcome. Our data support the hypothesis that a high TS level is a favourable prognostic factor in human untreated colorectal carcinomas according to our previous preliminary data (1).

5-Fluorouracil and recombinant alpha interferon-2a in the treatment of advanced colorectal carcinoma: a dose optimization study.

A dose optimization study was carried out with the aim of identifying the maximally tolerated dose of recombinant alpha interferon-2a (raIFN-2a) in combination with 5-fluorouracil (5FU). 5FU was given at the dose of 750 mg/m2 over a 4-hour infusion on day 1- - greater than 5 followed by 750 mg/m2 weekly i.v. bolus. Recombinant aIFN-2a was started at 3 x 10(6) IU subcutaneously three times/week. 12 patients with advanced colorectal carcinoma were included in the study. 10 patients had previously received chemotherapy for advanced disease. Severe fatigue, most likely attributable to rIFN, was the dose-limiting toxicity. The dosage of raIFN-2a could not be further escalated above 12 x 10(6) IU. At this dose level all patients required dose reduction due to fatigue, fever, myalgia and severe reduction of performance status.

Combination chemotherapy with cyclophosphamide, doxorubicin and vincristine in the treatment of stage III-IV small-cell lung cancer.

Twenty patients with histologically confirmed small-cell lung cancer were treated with cyclophosphamide 1000 mg/m2 i.v. on day 1, vincristine 1.4 mg/m2 i.v. day 1, and adriamycin 50 mg/m2 i.v. on day 1. This protocol was repeated every 21 days. Out of 17 evaluable patients 2 obtained a complete response (12%) with a mean duration of 11 months, 4 patients achieved a partial response with a mean duration of 6.3+ months, and 1 had a minimal response of 7.2 months. Two patients had a stabilization which lasted a mean of 4+ months, while 8 patients progressed. Although the mean survival was higher in responders than in non-responders, the difference in survival time was not statistically significant. The treatment was quite well tolerated with hematological toxicity in 78% of cases, oral and gastrointestinal toxicity in 83%, alopecia in 78%, and neurotoxicity in 16% of cases.