An Efficient Method for Culturing Human Breast Epithelium: Analysis of Results

We have examined the possibility of obtaining primary cultures from breast tissue utilizing a method especially developed for breast epithelium. The number of specimens able to grow in culture was very high: 82.8%, 64.3 %, 75.0 % and 77.8 %, respectively, for primary breast cancer, skin recurrences, inflammatory breast cancer and normal breast tissue. In our experience, growth was not related to menopausal status or histopathologic type, whereas for skin recurrences, a prior pharmacologic treatment (chemotherapy) of the patient enhanced the growth capacity of the tissue. This culture method could help to study the basic biology of breast epithelia and to improve the chemotherapy approach of breast cancer patients.

Radioligand-Labeled Binding Assay and Immunochemical Assay for Estrogen Receptor in 115 Human Breast Cancers

The aim of this study was to evaluate the results obtained from a new enzyme immunoassay (Abbott-ER-EIA) for the determination of estrogen receptor levels in tumor cytosols in comparison with the currently used DCC method. One hundred and fifteen consecutive primary breast cancer specimens were examined; 66 of the women were postmenopausal and 49 were premenopausal. A good correlation (r = 0.88, p < 0.001 and a slope of 1.3) was found between ER-EIA and the steroid binding assay (DCC). When these data were analyzed according to menopausal status, no differences were observed for the slopes and correlation coefficients in pre’ and postmenopausal groups. The ER-EIA appears to produce results comparable to those obtained with the conventional DCC method for the determination of ER in breast tumor cytosols.

N-Nitroso Compound Precursors and Gastric Cancer: Preliminary Data of a Study on a Group of Farm Workers

An epidemiological research on gastric cancer mortality rates carried out in the town of Forlì is reported. The results are significant as regards the relation between the urban and rural areas, and show a higher risk for gastric cancer in the rural area. Salivary nitrite measurement in 92 farm workers showed particularly high values (over 30 ppm in 4 individuals). Analysis of histological findings in biopsies performed during endoscopy in 46 persons of the group studied showed a great number of CAG and CAG + IM in asymptomatic individuals.

Role of BRAF molecular analysis in the management of papillary thyroid carcinoma: analysis of cytological and histological samples

BACKGROUND

Although fine needle aspiration (FNA) is the standard diagnostic test for the characterization of a suspicious thyroid nodule, in some cases cytological evaluation is inconclusive. The aim of this study was to determine the role of BRAF mutation in aiding diagnosis and to verify whether archival cytological samples could be suitable for molecular analysis.

METHODS

Eighty-five patients with suspicious (Thy4) or follicular (Thy3) lesions on cytology were resubmitted to a second FNA for BRAF mutation analysis. Of these, 56 subsequently underwent surgery. The usefulness of archival samples for molecular analysis was also studied in a second cohort of 42 patients with a confirmed diagnosis of papillary thyroid carcinoma for whom both archived paraffin-embedded histological samples and cytological smears were available. A further 15 patients with paired fresh FNA and archived cytological and histological samples were recruited.

RESULTS

BRAF mutation was found in the fresh FNA samples from 10 of 56 patients who had surgery with previous inconclusive cytology (4/45, 9%, Thy3 and 6/11, 55%, Thy4). The BRAF test showed a specificity and positive predictive value of 100% (26/26 and 10/10, respectively), sensitivity of 33% (10/30) and negative predictive value of 57% (26/46). There was absolute concordance between the BRAF results obtained with 42 histological and cytological archived samples. BRAF analysis on 15 archived cytological samples showed absolute concordance with histology, whereas there was one false negative on the matched fresh FNA.

CONCLUSION

BRAF analysis is a highly specific test that can facilitate cytological diagnosis in some cases and can also be performed on archived cytological samples.

FL-DNA approach for noninvasive early diagnosis of colorectal cancer in FOBT-screened patients

11062

Background: A promising approach for the early diagnosis of colorectal cancer (CRC) is the evaluation of genomic DNA integrity (FL-DNA) extracted from stool. Pilot and confirmatory studies carried out by our group have shown that, thanks to its diagnostic accuracy, this molecular assay could be a useful tool for the non-invasive, early diagnosis of CRC. The aim of the present study was to verify whether the FL-DNA method could represent a valid alternative to the fecal occult blood test (FOBT) or whether it could be used alongside FOBT in screening programs to unmask false FOBT positives and spare patients from unnecessary colonoscopy. For this purpose, stool samples were collected from all individuals participating in the FOBT (OC-Sensor, Alpha Wassermann) Regional Screening Program run by the Cancer Prevention Unit of Morgagni-Pierantoni Hospital in Forli. Methods: The program recruited subjects of either sex aged 50 to 69 years. Of the 560 individuals with FOBT-positive stool subjected to colonoscopy, 26 were diagnosed with adenocarcinoma, 264 with high-grade adenoma and 54 with low-grade adenoma. More than one third (216) of the group had only benign disease (hemorrhoids, diverticulitis, inflammation, etc), hyperplastic polyps or nothing. The integrity of fecal DNA was analyzed blindly by the FL-DNA test on the same specimen used for the occult blood determination. Results: Using a cut-off of 10 ng, the molecular analysis detected over 90% of the colorectal cancers and about 50% of the high- and low-grade adenomas. In particular, diagnostic accuracy was similar for lesions of any localization, level of dysplasia and histopathological characteristic, and higher for lesions > 2 cm and multiple lesions. The test also confirmed its capacity to identify colorectal cancer in asymptomatic individuals. Conclusions: FL-DNA represents a valid alternative to or support for approaches currently used in screening programs. A more in depth DNA stool evaluation in negative FOBT individuals could reveal the test's usefulness in unmasking colorectal tumors and adenomas missed by FOBT.

No significant financial relationships to disclose.

Translational study of the activity of liposomal doxorubicin formulations in hormone-refractory prostate cancer

e16026

Background: The efficacy of therapy for hormone-refractory prostate cancer (HRPC) is still unsatisfactory and new agents and therapeutic modalities are needed. The aims of the present work were to examine the in vitro activity and mechanisms of action of different doxorubicin formulations in HRPC cell lines and to assess the clinical potential of liposomal doxorubicin as second-line therapy in HRPC patients. Methods: Doxorubicin (Doxo), liposomal Doxo (Myocet) and pegylated liposomal Doxo (Caelyx) activity were assessed in vitro in PC3, DU145, and DU-R (partially resistant to docetaxel) cell lines by SRB test, and apoptosis was evaluated by TdT-assay and fluorescence image microscopy. On the basis of our in vitro results, a multicenter phase II trial was carried out in which a weekly administration of Myocet (25 mg/m2) and low-dose prednisone was given as second-line treatment after docetaxel failure. Objective responses were evaluated every nine weeks by PSA testing and by imaging for measurable lesions. Results: Myocet showed a higher cytotoxic activity than the other Doxo formulations in all cell lines, especially after a 72-h exposure, with already 70% of apoptotic cells at one tenth of the plasma peak concentration. Cytofluorimetry and fluorescence microscopy showed maximum Myocet concentration in the Golgi apparatus and at higher levels than those reached by the other Doxo formulations. The clinical trial completed the planned accrual of 43 patients and has achieved the principal endpoints of a PSA response (> 50%) in more than 20% of patients and of stable disease, at 9 weeks, in 38% of patients. Toxicity was generally mild, with grade 2 leucopenia and grade 3 neutropenia observed in only 2 patients. No serious drug-related adverse events were reported, and there were no cases of heart failure or of >10% decrease in LVEF. Conclusions: Myocet showed a higher activity on HRPC cells than the other Doxo formulations, which was probably due to a higher intracellular drug concentration, slower drug release and Golgi-dependent apoptosis. In the phase II study, Myocet and prednisone proved to be an effective and well tolerated regimen as second-line treatment for HRPC and warrant further evaluation.

No significant financial relationships to disclose.

Isolation of stem/progenitor cells from normal lung tissue of adult humans

OBJECTIVES

This study aimed to isolate and characterize stem/progenitor cells, starting from normal airway epithelia, obtained from human adults.

MATERIALS AND METHODS

Cultures of multicellular spheroids were obtained from human lung tissue specimens after mechanical and enzymatic digestion. Tissue-specific markers were detected on their cells by immunohistochemical and immunofluorescent techniques. Ultrastructural morphology of the spheroids (termed as bronchospheres) was evaluated by electron microscopy, gene expression analysis was performed by reverse transcription-polymerase chain reaction, and gene down-regulation was analysed by an RNA interference technique.

RESULTS

Bronchospheres were found to be composed of cells with high expression of stem cell regulatory genes, which was not or was only weakly detectable in original tissues. Morphological analysis showed that bronchospheres were composed of mixed phenotype cells with type II alveolar and Clara cell features, highlighting their airway resident cell origin. In addition to displaying specific pulmonary and epithelial commitment, bronchospheres showed mesenchymal features. Silencing of the Slug gene, known to play a pivotal role in epithelial-mesenchymal transition processes and which was highly expressed in bronchospheres but not in original tissue, led bronchospheres to gain a differentiated bronchial/alveolar phenotype and to lose the stemness gene expression pattern.

CONCLUSIONS

Ours is the first study to describe ex vivo expansion of stem/progenitor cells resident in human lung epithelia, and our results suggest that the epithelial-mesenchymal transition process, still active in a subset of airway cells, may regulate transit of stem/progenitor cells towards epithelial differentiation.

Pro-apoptotic activity of cyclopentenone in cancer cells

Studies on cyclopentenone prostaglandins (CPPGs), clavulones and other cyclopentenones have shown that these compounds have a significant anticancer activity mediated by their cyclopentenone (CP) chemical moiety. In this study the cytotoxicity against cancer cells of the model compound cyclopent-2-en-1-one (2CP) was investigated. Being a highly water soluble small molecule, 2CP could be an ideal candidate to overcome pharmacological issues related to drug delivery and penetration. Its cytotoxic activity was tested on various melanoma and lung cancer cells. Interestingly, 2CP was both cytotoxic and pro-apoptotic, more pronounced on melanoma cells, at concentrations in the sub-micromolar range. On melanoma cells its mechanism of action was mediated by the mitochondria and the activation of caspase 3.

Phase I study of paclitaxel and uracil plus tegafur combination in patients with pretreated metastatic breast cancer: drug sequencing based on preclinical modelling studies

OBJECTIVE

Taxanes and fluoropyrimidines are active in metastatic breast cancer (MBC), and their combination has proven effective in anthracycline-refractory patients. We conducted a phase I study to determine the maximum tolerated dose (MTD) of uracil plus tegafur (UFT) given in combination with leucovorin (LV) and paclitaxel (Pacl) in patients with refractory MBC.

METHODS

Pacl was infused at a fixed dose of 150 mg/m2 on day 1. UFT, at doses escalated by 50 mg/m2 starting from 200 mg/m2 . day, and LV, at a fixed dose of 90 mg/day, were given orally every 8 h for 11 days (days 3-13). Cohorts of at least 3 patients were treated at each dose level, and if 1 experienced dose-limiting toxicity (DLT), a maximum of 3 additional patients were added at the same dose level. MTD was reached if 2 out of the 6 patients experienced DLT.

RESULTS

Sixteen patients were enrolled in the study. The most important toxicity observed was hematological. Nonhematological toxicities were paresthesia and myalgia, asthenia, nausea, and mucositis. DLT occurred in only 1 patient (grade 3 hepatic toxicity).

CONCLUSIONS

The recommended dose for a subsequent phase II trial is Pacl 150 mg/m2 on day 1, and UFT 300 mg/m2 and LV 90 mg on days 3-13, every 2 weeks.

Cytotoxicity of different selective serotonin reuptake inhibitors (SSRIs) against cancer cells

Cell membrane ion transporters expression and activity are altered in cancer cells and these phenotypic alterations offer potential targets for cancer therapies. Among the therapeutic agents affecting cell membrane transporters, serotonin reuptake inhibitors (SSRIs) have been shown to have anticancer potential. In this work, we have compared two SSRIs, one very specific for serotonin reuptake transporters (paroxetine) and another which also inhibit norepinephrine and dopamine transporters (venlafaxine), for their ability to counteract growth of various murine and human cancer cell lines. We found that paroxetine has cytotoxic activity against tumor cells, both of murine or human origin in the micromolar concentration range, whereas venlafaxine has not. A neurotransmitter receptor mediated mechanism of action appears thus unlikely for SSRIs cytotoxicity on cancer cells. With ranges of SSRIs cytotoxicity on cancer cells defined, limits in their possible applicability in cancer therapy is discussed.

Phase II study of pegylated liposomal doxorubicin and oxaliplatin in relapsed advanced ovarian cancer

OBJECTIVE

This phase II study evaluated the efficacy and safety of pegylated liposomal doxorubicin (PLD) 30 to 35 mg/m(2) plus oxaliplatin 70 mg/m(2) every 28 days in women with advanced ovarian cancer that recurred or progressed after a platinum-based regimen.

METHODS

43 women received a median of 6 courses of treatment.

RESULTS

Objective response was 54% in the evaluable population and was higher in women with platinum-sensitive (67%) compared with platinum-resistant disease (29%). At a median duration of follow-up of 15.5 months, median overall survival was 15.8 months and time to tumor progression 7.3 months. Most toxicity was no greater than grade 1 or 2. There was no grade 3 or 4 palmar-plantar erythrodysesthesia. After 264 cycles administered, neutropenia was the most common cause of severe toxicity and required one patient to withdraw from the study. No cardiotoxicity was reported.

CONCLUSION

PLD plus oxaliplatin is active and well tolerated in women with relapsed advanced ovarian cancer, regardless of platinum sensitivity.

Modulation of drug cytotoxicity by Iressa (ZD1839) in pancreatic cancer cell lines

High expression of the epidermal growth factor receptor (EGFR) family confers a growth advantage on malignant cells in various tumor types. Most pancreatic cancers express EGFR, which seems to play an important role in the acquisition of aggressive clinical behaviour and in tumor invasion. Iressa (ZD1839), a quinazoline tyrosine kinase inhibitor selective for the EGF receptor, has shown good anti-tumor activity in both preclinical and clinical studies. Using two pancreatic cancer cell lines that express different EGFR and ErbB-2 levels, we analyzed the activity of Iressa and evaluated its modulation effect on four conventional cytotoxic drugs: gemcitabine, oxaliplatin, docetaxel and SN38. Iressa was tested at scalar doses up to the plasma peak level concentration and showed a similar weak cytostatic effect in both cell lines. Conversely, an additive or weak synergistic effect was observed when the drug was administered simultaneously with or following cytotoxic drugs. Our data show that Iressa has only a weak activity at doses within the plasmatic peak concentration and that its effect is independent of EGFR and p42/p44 expression and phosphorylation levels. This is in agreement with recent literature data that attribute an essential role to a specific EGFR mutation in mediating response to Iressa. This mutation was absent in both pancreatic cell lines tested.

Pro-apoptotic effect of a nitric oxide-donating NSAID, NCX 4040, on bladder carcinoma cells

Nitric oxide-releasing non steroidal anti-inflammatory drugs (NO-NSAIDs) are a promising class of compounds that cause cell cycle perturbations and induce apoptosis in cell lines from different tumors. We investigated the activity of a recently developed NO-NSAID (NCX 4040) in bladder cancer cell lines (HT1376 and MCR). Cells were treated with different drug concentrations for different exposure times. Cytostatic and cytocidal activity was tested by SRB assay and apoptosis was evaluated by TUNEL analysis, ANNEXIN V assay and fluorescence microscopy. To further investigate the cell death-inducing mechanisms of NCX 4040, we analyzed gp-170, caspase expression and mitochondrial membrane potential (Delta Psi) depolarization. NCX 4040 showed a striking cytocidal activity in both cell lines, reaching LC(50) at a 10-microM and 50-microM concentrations in HT1376 and in MCR cells, respectively, after an exposure of only 6 h followed by an 18-h washout. Apoptosis was triggered in up to 90% of cells and was associated with active caspase-3 expression and Delta Psi depolarization in both cell lines after a 6-h exposure. In conclusion, NCX 4040, which probably causes apoptosis via a mitochondrial-dependent mechanism, could prove to be a useful agent for improving bladder cancer treatment.

Doxorubicin, paclitaxel and gemcitabine: a Phase I study of a new sequential treatment in stage III B - IV breast cancer

Based on the synergistic interactions of the sequence doxorubicin-paclitaxel-gemcitabine obtained in our preclinical study, a Phase I trial was conducted to evaluate the feasibility of this new sequence in breast cancer. Patients with stage IIIB-IV breast cancer received doxorubicin on day 1, paclitaxel on day 2 and gemcitabine on day 6 and 13 (steps IIa, III and V) in cohorts of 3 patients. From March 1999 to December 2000, 9 patients were treated. The most important toxicity was hematological. The maximum tolerated dose was reached at the second level because dose-limiting toxicity occurred in 3 patients. Non hematological toxicities were alopecia, diarrhea, asthenia, nausea, mucositis, paresthesia and myalgia. A Phase II trial is ongoing to further investigate the activity of this new sequential treatment with doxorubicin (50 mg/m2 day 1), paclitaxel (160 mg/m2 day 2) and gemcitabine (800 mg/m2 day 6) in advanced breast cancer.

Potentiation of antiproliferative drug activity by lonidamine in hepatocellular carcinoma cells

The ability of lonidamine (LND), a derivative of indazole-carboxylic acid, to modulate the cytotoxic activity of anticancer drugs was investigated in two human hepatocarcinoma (HCC) cell lines. The cytotoxicity of drugs used singly, in association or in sequence was evaluated using the Sulforhodamine B (SRB) assay. LND did not appreciably potentiate the effect of antitumor drugs when given before or simultaneously, in either cell line. Conversely, a synergistic interaction was observed in both cell lines when LND was given after conventional drugs. LND produced a moderate decrease in S-phase cell fraction and did not induce apoptosis. Conversely, paclitaxel (TAX) induced an important block in G2 and an increase in apoptosis. Following a 48-h TAX wash out, a progressive passage of cells from G2 to M phase was observed with a corresponding increase in apoptotic cells. Post-treatment with LND increased the cytotoxicity of some antitumor drugs, especially TAX, in hepatocarcinoma cells, possibly by preventing, as an energolytic drug, cell damage repair or by producing an additional effect on microtubule stabilization.

Role of biological markers in the clinical outcome of colon cancer

We investigated a number of biological markers, evaluated under strict intralaboratory quality control conditions, in terms of their role in predicting clinical outcome of patients with colon cancer treated with 5-FU-containing regimens. Colon cancer tissue from 263 patients enrolled onto two randomised clinical trials were studied for their cytofluorimetrically determined DNA content and their immunohistochemically evaluated microvessel density, vascular endothelial growth factor expression, thymidylate synthase expression and tumour lymphocyte infiltration. Disease-free survival and overall survival of patients were analysed as a function of the different variables. At a median follow up of 57 months, age, gender and Dukes' stage showed an impact on disease-free survival, whereas no biological marker emerged as an indicator of better or worse disease-free survival. Only histological grade and Dukes' stage were found to influence overall survival. The different biological variables, studied with particular attention for determination reliability, proved to have no impact on the clinical outcome of patients with colon cancer. Therefore, other markers must be identified to complement clinico-pathological variables in the management of this disease.

Flow-cytometric determination of tumor cells in lymph nodes

In solid tumors, metastasis occurs through the dissemination of tumor cells in the bloodstream and the lymphatic system. In particular, lymph node infiltration gives useful prognostic information and represents one of the most important factors for selecting the type of clinical treatment in disease management. Furthermore, the analysis of lymph node infiltration has become important for identifying patients with breast cancer or malignant melanoma who may be candidates for regional lymph node dissection. Tumor cells in lymph nodes are currently identified in tissue sections using morphological and immunohistochemical analyses, but these approaches are time-consuming, and micrometastases may escape detection. The aim of the present study was to define the potential of a flow cytometric (FCM) determination based on cell size and autofluorescence to shorten the time required for lymph node analysis. The sensitivity of the FCM approach, defined on mixtures of tumor cells from established cell lines and peripheral blood lymphocytes (PBL(s)) at different concentrations, was 1 tumor cell/1,000 PBL(s). FCM analysis was performed on 89 lymph nodes, 29 from breast, 41 from lung and 19 from colon cancer patients. Agreement between FCM and morphological results, used as gold standard, was observed in 83% of the cases, and there was a 90% sensitivity to the FCM approach for each tumor type. Disagreement was observed for 15 lymph nodes and was due, in the majority of cases (80%), to FCM-positive and morphologically negative results. A large number of patients and a more accurate pathological examination of consecutive histological sections of lymph nodes are needed to further evaluate the validity of the FCM approach.

Comparison between different cell kinetic variables in human breast cancer

Cell kinetics holds a prominent role among biological factors in predicting clinical outcome and response to treatment in neoplastic patients. Different cell kinetic variables are often considered as valid alternatives to each other, but the limited size of case series analysed in several studies and the lack of simultaneous determinations of all the variables on the same tumours do not justify this conclusion. In the present study, the correlation between [3H]thymidine labelling index ([3H]dT LI), flow cytometric S phase cell fraction (FCM-S) and Ki-67 immunoreactivity (Ki-67/MIB-1) was verified and the type of correlation with the most important clinical, pathological and biological patient and tumour characteristics was investigated in a very large series of breast cancer patients. Ki-67/MIB-1, FCM-S and [3H]dT LI were determined in 609, 526 and 485 patients, respectively, and all three cell proliferation indices were evaluated in parallel on the same tumour in a series of 330 breast cancer patients. All the cell kinetic determinations were performed within the context of National Quality Control Programmes. Very poor correlation coefficients (ranging from 0.37 to 0.18) were observed between the different cell kinetic variables determined in parallel on the same series of breast cancers. Moreover, Ki-67/MIB-1 and FCM-S showed a significant relationship with histological type, grade and tumour size, whereas statistically significant correlations were not observed for [3H]dT LI. In conclusion, the results show that the different cell kinetic variables provide different biological information and cannot be considered as alternatives to each other.

Simultaneous determination of apoptosis and surface antigen expression in tumor adherent cells

Apoptosis is a physiological, gene-directed form of cell death aimed at controlling cell proliferation in several biological conditions. It plays a crucial role in modulating tissue growth during embryonic development, cell turnover in adult life, and it seems to be the most frequent mechanism of tumor cell deletion by chemotherapy. Flow cytometry is a widely-used technique for checking apoptosis, permitting a multiparametric analysis. It is possible to follow the alterations occurring in the nucleus, mitochondria and plasmatic membrane during the different apoptotic stages using probes such as LDS-751, JC-1 or Annexin V. The potential of these probes to identify the early or late stages of apoptosis has been widely investigated in cells growing in suspension. In order to assess apoptosis in adherent cells, we tested a combination of fluorescein diacetate (FDA), a substrate for non specific esterase whose activity decreases during the early phase of apoptosis, and trypan blue in MCF-7 human breast cancer cells. Apoptotic cells showed a decrease in the green fluorescence emitted by fluorescein, the product of FDA hydrolysis, whereas necrotic cells emitted a red fluorescence due to the trypan blue staining. FDA-trypan blue double-staining was used to investigate the different kinetics of apoptosis induced by taxol, camptothecin and UV-B irradiation in MCF-7 cells. This method is rapid and simple, and can be used for monitoring the process of apoptosis from early stages in adherent cells, for the physical separation of apoptotic and live cells, and for immunophenotyping, including Fas expression.

Multiple detection of genetic alterations in tumors and stool

Detection of genetic alterations in exfoliated intestinal cells in stool could represent an alternative, noninvasive tool for the screening of colorectal tumors. To verify this, we analyzed p53 and K-ras mutations and microsatellite instability on 46 cases of colorectal cancer and compared the presence of molecular alterations in tumor tissue and stool samples from individual patients. p53 exons 5-8 and K-ras exons 1-2 were analyzed by denaturing gradient gel electrophoresis. For the microsatellite instability, a set of 5 microsatellite markers (D2S123, D5S346, D17S250, BAT25, and BAT26) was evaluated. In the 18 healthy individuals, no genetic alterations in either tissue or stool were detected. p53 mutations were detected in 17 (37%), K-ras alterations in 15 (33%), and microsatellite instabilities in 5 (11%) of the 46 tumors analyzed. In a side study, we analyzed the correlation in genetic alteration profiles between tumors and macroscopically normal or healthy tissue from the same patient. The presence of at least one molecular alteration in tumor was observed in 31 (67%) of the cases. p53, K-ras mutations, and microsatellite instabilities were detected in stool samples in 18, 40, and 60% of patients with tumors harboring the same alterations. Due to the largely complementary presence of p53 and K-ras mutations in tumors, the use of highly sensitive procedures for stool analysis could offer a means competitive with colonoscopy and the fecal occult blood test.

In vitro preclinical models for a rational design of chemotherapy combinations in human tumors

Today, drug combinations are frequently used in the treatment of cancer to increase therapeutic efficacy. Currently used clinical protocols for cancer combination therapies are mainly obtained empirically or on the basis of results from previous clinical trials. Information obtained from clinical protocols is invaluable, but it is time-consuming, expensive and does not provide data on the biochemical and molecular mechanisms of interaction of the drugs used in combination treatments at cellular level. Therefore, in vitro drug combination studies on established cell lines or primary cell cultures play an important role in designing and optimising combination protocols. A variety of in vitro assays and different mathematics models have been developed to investigate cytotoxic effects and to analyse the type of drug interactions. Increased knowledge of the cellular targets of traditional and new drugs and the development of new technologies have resulted in a new role for the in vitro tests which are no longer used only to evaluate the cytotoxic effects of drugs, but also to investigate the interference on cell cycle, induction of apoptosis and molecular or biochemical interactions. A review on in vitro preclinical tests used to evaluate the effects of drug combinations and to design the rationale of combined chemotherapy protocols is presented.

Lanreotide-induced modulation of 5-fluorouracil or mitomycin C cytotoxicity in human colon cancer cell lines: a preclinical study

The effect on growth of the long-acting somatostatin analogue lanreotide (LAN), alone or in combination with 5-fluorouracil (5-FU) and mitomycin C (MIT), was investigated in three human colon cancer lines. Cell survival inhibition induced by LAN alone, as evaluated by sulforhodamine B assay, ranged from 20% to 40% as a function of cell line and concentration. The IC50, the concentration inhibiting cell survival by 50%, was never reached. The antiproliferative effect produced by a 48 h exposure to 5-FU or MIT was synergistically enhanced in all cell lines by a subsequent 48 h exposure to LAN. The synergistic interaction was not related to specific cell cycle perturbations or to the somatostatin receptor 2 (sst2) mRNA abundance. In conclusion, our study seems to indicate that LAN is a potentially useful modulating agent for enhancing 5-FU and MIT activity in colorectal cancer patients.

Combined 4-hydroxy-ifosfamide and vinorelbine treatment in established and primary human breast cell cultures

BACKGROUND

Vinorelbine and ifosfamide are active drugs against breast cancer, but the best treatment schedule has yet to be defined by preclinical or clinical studies. The antitumor activity of 4-hydroxy-ifosfamide (4-OH-IF), the active form of ifosfamide, and vinorelbine (VNB) and their interaction were investigated in two established breast cancer cell lines (MCF-7 and BRC-230) and in 10 primary breast cancer cultures.

MATERIALS AND METHODS

Cytotoxic activity was evaluated by a highly efficient clonogenic assay (HECA). The median-effect principle was applied to evaluate synergistic and antagonistic interactions and the corresponding combination index values were calculated. Cell cycle perturbations were analysed by flow cytometry.

RESULTS

In MCF-7 and BRC-230 cell lines the sequence VNB for 4 hours followed by 4-OH-IF for 24 hours produced an antagonistic effect. Conversely, the inverse sequential scheme, 4-OH-IF-->VNB provided synergistic effects on both cell lines. The synergism was associated with a strong block in the G2-M phase. Synergistic activity of 4-OH-IF-->VNB sequence was confirmed in 7 of 10 primary breast cancer cultures.

CONCLUSIONS

In conclusion, the sequence 4-OH-IF-->VNB appeared to be the most effective scheme both in established cell lines and in primary breast cancer cultures.

Correlation between p53 gene mutations and p53 protein accumulation evaluated by different methodologies

Mutations in the p53 gene are the most common genetic alterations in many tumour histotypes. Many of these mutations induce conformational changes resulting in p53 protein stabilisation and consequently an accumulation detectable with immunochemical methods. Available data on the correlation between p53 gene alterations and p53 overexpression widely vary. In this study we analysed the correlation between p53 gene alterations detected by DGGE, SSCP and sequencing and protein expression detected by flow cytometric and immunohistochemical approaches by using PAb 1801 antibody. The study was performed on 21 bladder tumours and 10 cell lines derived from different tumour histotypes as representative of different methodologic problems which can be met starting from different types of biological material. The best correlation (81%) was observed between p53 mutations and FCM results, using a double evaluation criterion for the latter which includes the percentage of positive cells and "delta values", evaluated as the difference between the mean values of Pab 1801 stained cells and isotypic control. The high correlation obtained between results from this FCM double criterion and p53 gene mutations is a good starting point for the analysis on large series of tumours and for a multiparameter FCM analysis including p53 protein levels.

Docetaxel and gemcitabine activity in NSCLC cell lines and in primary cultures from human lung cancer

The activity of the following drugs was investigated in two established NSCLC cell lines: docetaxel, gemcitabine, vinorelbine, paclitaxel, doxorubicin (0.01, 0.1, 1 microg ml(-1)), cisplatin, ifosfamide (1, 2, 3 microg ml(-1)) and carboplatin (2, 4, 6 microg ml(-1)). The cytotoxic activity was evaluated by the sulphorhodamine B assay. The two most active drugs, docetaxel and gemcitabine, used singly and in association, were investigated as a function of treatment schedule. The sequence docetaxel-->gemcitabine produced only a weak synergistic interaction in RAL but a strong synergism in CAEP cells. The synergistic interaction increased in both cell lines after a 48-h washout between the drug administrations. Flow cytometric analysis showed that in docetaxel-->gemcitabine sequence, docetaxel produced a block in G2/M phase and, after 48 h, provided gemcitabine with a large fraction of recovered synchronized cells in the G1/S boundary, which is the specific target phase for gemcitabine. Conversely, simultaneous treatment induced an antagonistic effect in both cell lines, and the sequential scheme gemcitabine-->docetaxel produced a weak synergistic effect only in RAL cells. Moreover, the synergistic interaction disappeared when washout periods of 24 or 48 h between two drug administrations were adopted. The synergistic activity of docetaxel-->48-h washout-->gemcitabine was confirmed in 11 of 14 primary cultures, which represents an important means of validating experimental results before translating them into clinical practice.

Schedule-dependent interaction of doxorubicin, paclitaxel and gemcitabine in human breast cancer cell lines

We showed previously that a sequential treatment with doxorubicin (4 hr) followed by paclitaxel (24 hr) (Dox-->Pacl) induces a synergistic cytotoxic effect in the BRC-230 breast cancer cell line and in human primary breast cancer cultures. The validity of this experimental finding was confirmed in a clinical phase I/II study on advanced breast cancer patients. To improve the cytotoxic effect obtained by the Dox-->Pacl sequence, we analyzed the effect of adding gemcitabine (Gem) to the Dox-->Pacl sequence in a preclinical study. Our study was performed on BRC-230 and MCF-7 cell lines, and cytotoxic activity was evaluated by the sulforhodamine B assay and the type of drug interaction by Drewinko's test. When Gem (0.01 microg/ml for 24 hr) was given immediately or 24 hr after Dox-->Pacl, an antagonistic cytotoxic effect was observed. Conversely, a synergistic effect was found when Gem was given 48 hr after Dox-->Pacl. From results of flow cytometric analysis, the synergistic effect was attributed to cell cycle perturbation. Cells were arrested in G2-M (95% in treated vs. 21% in control samples) 24 hr after Dox-->Pacl treatment. The block progressively recovered thereafter, and after a further 24 hr, at the time of Gem treatment, the cells progressed into the G1-S phase boundary (the cell cycle phase susceptible to the cytocidal effect of the drug). Our findings suggest that the interactions of Dox, Pacl and Gem are highly schedule- and time-dependent and should be taken into consideration in the planning of clinical protocols.

Molecular and biological features of two new human squamous and adenocarcinoma of the lung cell lines

Two human cancer cell lines were established from metastatic lesions of an adenocarcinoma (RAL) and a squamous cell (CAEP) carcinoma of the lung. The clinical histories of the patients from whom the cell lines were derived are reported. The lines were maintained in continuous culture with doubling times of 65 (RAL) and 50 (CAEP) hours. The RAL and CAEP cell lines, whose morphology and ultrastructural features are presented, showed extensively rearranged karyotypes with modal number of 85 (RAL) and 98 (CAEP). In particular, chromosome 2 pentasomy and several clonal markers were evident in the RAL cells, whereas a telomeric deletion of chromosome 1, del (1)(q32), was observed in the CAEP cells. The morphologic data were confirmed by high expression of specific antigens for each histotype. A marked positivity of the neuron-specific enolase (NSE) levels was evident by immunoenzymatic assays in the cell lines cytosol with respect to those present in the respective patient's sera. No amplification or rearrangements were evident in the CMYC, LMYC, NMYC, INT-2, ERBB2, HRAS, KRAS, MOS, HST-1 genes by Southern blotting analysis in each cell line. Point mutations in exon 1 of KRAS and in exon 7 of TP53 were evident by polymerase chain reaction (PCR)-DNA sequencing in the RAL cell line, whereas no alterations were present in the HRAS and RB genes. The four genes studied did not show point mutations in the CAEP cell line. The RAL cell line was resistant to all the drugs tested, whereas the CAEP cells were sensitive to vinblastine. These cell lines may represent useful experimental models to investigate lung cancer biology and anticancer drug response.

Different genome organization in two new cell lines established from human gastric carcinoma

Two gastric cancer cell lines, AKG and GK2, were established from a pleural and an ascitic effusion, respectively. GK2 cells have a pseudodiploid karyotype with an add(6)(q27) chromosome in all metaphases examined. The karyotype of AKG cells is highly rearranged: FISH analysis with painting probes has shown that DNA sequences derived from single chromosomes are scattered on several (as many as eight) markers. In this cell line, the C-MYC and the K-RAS oncogenes are amplified. The organization and the copy number of the C-MYC-amplified units are different from the K-RAS units, suggesting that the two oncogenes were amplified independently. The presence of a few marker chromosomes carrying both C-MYC and K-RAS could be due to translocation events that followed the amplification.

Molecular genetics and in vitro sensitivity of a new human cell line, KKP, from a gastric adenocarcinoma

A new cancer cell line (KKP) was established from an ascitic effusion of an advanced gastric adenocarcinoma, intestinal type. The line has been maintained in continuous monolayer culture with a doubling time of 48 hours for more than 2 years. KKP cells, whose ultrastructural features are presented, showed an aneuploid DNA content, a modal number of 53 chromosomes, and the presence of one double minute chromosome. The karyotype showed trisomies of chromosomes 7, 12, 13, and 14, tetrasomy of chromosome 18, a reciprocal translocation [t(1;20)(q21;p11.2)], and a [t(4;?)] rearrangement. No amplification or rearrangements were evident in the c-MYC, c-ERB B2, H-RAS, INT-2, HST-1, c-MOS, and K-RAS genes, whereas somatic rearrangements were present in the sequences corresponding to c-MET and cyclin E genes by Southern blotting analysis. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis of P53 and RB genes did not reveal alterations or point mutations in the SSCP pattern of conformers. The chemosensitivity pattern assay of the KKP cell line indicated that it was sensitive to cisplatin, etoposide, and doxorubicin and resistant to 4'-hydroperoxycyclophosphamide. The clinical history of the patient from whom the cell line was derived is reported and compared with the results observed in the cell line in vitro. High levels of the tumor-associated antigens CEA (carcinoembryonic antigen) and CA19-9 were evident in the KKP cytosol, whereas the KKP spent culture medium maintained the same low levels of CEA and CA 19-9 found in the patient's serum. This new cell line may represent a useful tool for studying the biology of gastric cancer and for planning new therapeutic approaches.

Modulating effect of lonidamine on response to doxorubicin in metastatic breast cancer patients: results from a multicenter prospective randomized trial

Previous results from our preclinical studies have shown that lonidamine (LND) can positively modulate the antiproliferative activity of doxorubicin (DOX) on breast cancer cell lines. To evaluate the effect of LND in a clinical setting, a multicenter randomized trial was carried out on patients with advanced breast cancer. From September 1991 to July 1993, 181 patients were enrolled in the trial and received an initial treatment of DOX at 75 mg/m2 for 3 cycles. The 137 patients who reached complete remission, partial remission, or stable disease were randomized to receive either DOX alone (75 mg/m2 day 1) (arm A) or DOX plus LND (600 mg orally/day) (arm B). The patients enrolled in the two arms were fairly homogeneous in terms of major clinical characteristics. Toxicity was similar in both arms except for myalgia: WHO grade > or=2 was observed in 57% of arm B patients. Overall response rate to DOX + LND was 50% and to DOX alone 38% in evaluable patients, and 48% vs 37% in all registered patients, as determined by an intention-to-treat analysis. The differences did not reach statistical significance. Conversely, in agreement with previous findings, we observed a significant difference in response rate in the subgroup of patients with liver metastases, regardless of the extent of hepatic involvement (DOX + LND 68% vs DOX 33%, p=0.03). This observation makes LND an important tool in association with anthracyclines in the treatment of this subgroup of patients.

Chromosomal alterations, biological features and in vitro chemosensitivity of SCLC-R1, a new cell line from human metastatic small cell lung carcinoma

A new human cancer cell line was established from a metastatic lesion of a small cell lung carcinoma (SCLC-R1) and maintained in continuous culture with a doubling time of 62 h. The SCLC-R1 line, whose ultrastructural features are presented, showed a diploid DNA content, a translocation involving chromosome 16 [t(16;?)(q24;?)] and noticeable deletions in the FHIT (fragile histidine triad) region in the short arm of chromosome 3 [del(3)(p14)] and in the telomeric region of the short arm of chromosome 12 [del(12)(p13)]. The involvement of 12p in metastatic small cell lung cancer is reported here for the first time. No amplification or rearrangements were evident in the c-myc, L-myc, N-myc, int-2, c-erbB-2, H-ras, K-ras, c-mos, and hst-1 genes by Southern blot analysis. Wild-type p53, RB, K-ras and H-ras genes were evident by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis. The neuron specific enolase (NSE) level was much higher in the cell line's cytosol than in the patient's serum and the cell line also had high expression of chromogranin A and cytokeratin 19. SCLC-R1 cells were sensitive to cisplatin, carboplatin and doxorubicin. The clinical history of the patient from whom the cell line was derived is reported. The characteristics of this new cell line indicate it to be a useful experimental model to investigate lung cancer biology and anticancer drug response.

Paclitaxel plus doxorubicin in breast cancer: an Italian experience

Based on preclinical data, phase I/II clinical trials were performed at Istituto Oncologico Romagnolo (IOR) Operative Units (Medical Oncology Departments of Forlì, Rimini, and Ravenna, Italy) to determine the efficacy and toxicity of sequential administration of doxorubicin followed by paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) in the treatment of patients with advanced breast cancer that either had been previously untreated or that had relapsed after adjuvant therapy. In the phase I trial, 19 patients received bolus doxorubicin (50 mg/m2) followed after a 16-hour interval by paclitaxel (given at dose levels ranging from 130 to 250 mg/m2) by 3-hour infusion every 3 weeks, for a maximum of eight cycles. Paclitaxel doses were escalated in 30-mg/m2 increments if the maximum tolerated dose had not been reached in the previous dose level. Analysis of the 128 cycles assessable for toxicity demonstrated neutropenia (<500/microL) in 26 courses (20.3%), with no significant clinical events. No relevant clinical cardiotoxicity was observed. The paclitaxel maximum tolerated dose was not reached at the 250-mg/m2 dose level (no grade 3 or 4 extramedullary toxicity). In the IOR phase II trial, 13 patients were treated with fixed doses of both drugs (doxorubicin 50 mg/m2 and paclitaxel 220 mg/m2). Grade 4 neutropenia occurred in 39 of the 95 cycles, but was complicated by fever in only eight cycles (8.4%); three cycles required granulocyte colony-stimulating factor support. Peripheral neurotoxicity was the most common extramedullary side effect noted. Overall clinical responses in the IOR trials included 10 complete responses (31.3%) and 15 partial responses (46.9%), with an objective response rate of 78.1%. Comparison of these results with those obtained from a phase I trial using the opposite drug sequence showed comparable overall response rates, but IOR's sequence was associated with a higher complete response rate, as well as less frequent and less severe nonhematologic toxicity.

Establishment and characterization of two new cell lines derived from human metastatic breast carcinomas

Two human cancer cell lines (MA 2 and MA 3) were established from pleural effusions of infiltrating ductal carcinomas of the breast. The lines were maintained in continuous monolayer culture with doubling times of 70 (MA 2) and 78 (MA 3) hr for more than two years and possessed extensively rearranged abnormal karyo-types with modal chromosome number of 83 (MA 2) and 81 (MA 3) and DNA index values of 1.65 and 1.77, respectively. No amplifications or rearrangements were evident in the c-myc, int-2, c-erb B2, c-Ha-ras, or hst 1 genes in MA 2 and MA 3 cell lines. The clinical histories of the patients from whom the cell lines were derived are reported and compared with the results observed in the cell lines in vitro. The presence of CEA, CA 15-3, and MCA tumor markers observed in the primary tumor tissues was retained by the established cell lines. While the primary tumor tissues were ER+/PgR borderline+ (MA 2) and ER-/PgR+ (MA 3), the MA 2 line was ER+/PgR- and the MA 3 line remained ER-/PgR+. The MDR P-glycoprotein was not expressed either in primary tumor tissues or in the respective cell lines. High expression of cytokeratins 7, 18, and 19 was evident by immunohistochemical analysis in each cell line. whereas cytokeratins 8 and 17 were poorly or not at all expressed. The treatment history of the patients from whom the cell lines were derived involved CMF followed six months later by novantrone and cisplatin plus VP 16 (MA 2) and FEC followed four years later by CMF (MA 3). The chemosensitivity pattern assay of the cell lines indicated that the MA 2 line was sensitive to doxorubicin, cisplatin, and vinblastine, whereas the MA 3 line was sensitive to doxorubicin and cisplatin. The characteristics of these cell lines indicate them to be a good experimental model to investigate breast cancer biology and anticancer drug response.

Doxorubicin and paclitaxel (sequential combination) in the treatment of advanced breast cancer

Based on preclinical data, we designed a phase I/II clinical trial to determine the efficacy and toxicity of doxorubicin followed by paclitaxel in the treatment of advanced breast cancer (either untreated or relapsed after adjuvant therapy). In the phase I dose-finding study, 19 enrolled patients received bolus doxorubicin (50 mg/m2) and, after a 16-hour interval, a three-hour infusion of paclitaxel in escalating doses from 130 to 250 mg/m2, increased by 30-mg/m2 increments for each dose-level group. The first dose level group (paclitaxel 130 mg/m2) included three patients. The other dose level groups included four patients. Treatment was repeated every three weeks for a maximum of eight cycles. The paclitaxel dose was escalated to 250 mg/m2 without reaching the maximum tolerated dose. In the 128 cycles assessable for toxicity, there were no relevant clinical signs or symptoms of cardiotoxicity. This absence of significant cardiotoxicity required confirmation in a phase II trial. Since a maximum tolerated dose of paclitaxel had not been reached during the first study and an increasing risk of neutropenia and peripheral neurotoxicity was feared if doses continued to escalate, a phase II confirmatory study was begun to evaluate treatment with fixed doses of doxorubicin (50 mg/m2) and paclitaxel (220 mg/m2), using the same schedule and interval as in phase I. The 13 patients enrolled in phase II received a total of 95 cycles of therapy; in 10 cycles (three patients) dose reductions were necessary because of toxicity. However, no significant clinical cardiotoxicity was observed in 12 of the 13 patients. One patient experienced an asymptomatic, transient decrease in left ventricular ejection fraction at a cumulative doxorubicin dose of 400 mg/m2. Overall clinical responses included 10 complete remissions (31.3%) and 15 partial remissions (46.9%) for an objective response rate of 78.1%. At 16 months' median follow-up, the median time to progression for all patients is nine months. The high response rate obtained in the phase I/II studies and, in particular, the absence of significant cardiotoxicity require confirmation in further clinical trials. To date, two confirmatory phase II trials are ongoing in our institutions.

Saporin 6 and lonidamine in primary cell cultures from human breast carcinomas: a synergistic effect

Lonidamine (LND) is a potential chemotherapeutic agent which can positively modulate the efficacy of several antineoplastic agents. The ribosome-inactivating protein Saporin 6 (SO 6), which acts as a rRNA N-glycosidase and a DNA nuclease, has recently attracted interest as a novel potential anticancer and antiviral agent. Synergism between LND and SO 6 was previously demonstrated by us in the human metastatic MAST breast cancer cell line in vitro. In the present study, the antiproliferative effect of the drugs, either alone or in combination, was investigated in vitro at various concentrations in 17 primary cell cultures established from patients carrying infiltrating ductal carcinomas of the breast. Results indicate a strong synergistic effect in 11/17 cases, when LND was administered as a second drug. This is in agreement with previous results in the MAST cell line. Synergism was evident at SO 6 concentrations between 3.3 x 10(-10) and 1.7 x 10(-9) M.