Antiapoptotic effect of c-fes protooncogene during granulocytic differentiation

The c-fes protooncogene is expressed at high levels in the terminal stages of granulocytic differentiation. Its product, p92c-fes, exhibits a tyrosine-kinase activity and is involved in the cellular response to GM-CSF, but its role is not yet clarified. To study this problem, the c-fes protooncogene expression has been inhibited in HL60 cells and in fresh leukemic blast cells of Acute Promyelocytic Leukemia (APL) induced to differentiate with All-Trans-Retinoic Acid (ATRA). Inhibition of c-fes function was obtained by treatment of the cells with a specific antisense oligomer complementary to the 5' region of the c-fes mRNA. It was observed that the cells, rather then differentiate to granulocytes, underwent premature cell death showing the morphological and molecular characteristics of apoptosis. Superimposable results are obtained on blast cells from APL. It is possible to conclude that the loss of cell viability that occurs during the in vitro differentiation of myeloid cells, after the complete inhibition of c-fes expression and treatment with ATRA, is due to activation of programmed cell death rather than an accelerated differentiation. Our data suggest that the c-fes product is essential for the survival of myeloid cells during differentiation.

Gastric cancer cell DNA content correlates with early and late results after gastrectomy

The DNA content of 59 adenocarcinomas of the stomach in patients who had undergone subtotal or total gastrectomy more than 5 years before was measured. The DNA measurements were done by flow cytometry performed on Propidium Iodide--stained cells disaggregated from paraffin-embedded tissues. Fifty-nine evaluable good quality histograms of DNA ploidy patterns were obtained. The Proliferative Index (PI) was determined in 35 cases. The remaining 24 cases didn't show a reliable reading histograms. Of the 59 tumors, 33 (56%) were diploid and 26 (44%) were aneuploid; 19 showed a high PI (> or = 3.8%) and 16 a lower one. A statistically significant difference was found between the two groups (diploid/aneuploid and low/high PI) compared to the prognostic values known as T, N and Stage. 65% of the T3-T4 cancers, 54% of the N1-N2 lesions and 58% of the stage III and IV were found to be aneuploid. 73.7% of the 19 tumors presenting high PI, showed an aneuploid pattern. A high PI was found in 71.4% of the T3-T4 tumors. 77.4% of patients of the diploid group (any stage) survived at 5 years against 36% of those presenting aneuploid patterns. Patients with PI > or = 3.8% showed a 42.1% 5-year survival rate. A 94.4% 5-year survival rate of diploid and early stage cancers was documented against a 33.5% of aneuploid and advanced stage cancers.

Inhibition of leukaemia cell proliferation by folic acid-polylysine-mediated introduction of c-myb antisense oligodeoxynucleotides into HL-60 cells

The inhibitory effect of c-myb antisense oligodeoxynucleotides (ODNs) conjugated to folic acid (FA) on HL-60 cell proliferation was examined. Folic acid was covalently linked to a polylysine chain and purified by gel chromatography. Sterile FA-polylysine was complexed with c-myb sense and antisense. Exposure of HL-60 cells to the FA-polylysine-c-myb antisense ODN complex resulted in a down-regulation of c-myb expression and a greater inhibition of proliferation than that obtained using free ODNs. Moreover, FA-polylysine conjugate alone or complexed to c-myb sense ODN was not toxic to cells. The antigenic properties and uptake of the vitamin were not affected by the polylysine chain. These data suggest that this strategy is potentially useful for the selective delivery of anti-oncogene-targeted ODNs into cancer cells.

Effects of sequential combinations of N-methylformamide with adriamycin on cultured melanoma cells (M14)

The effects of sequential combinations of N-methylformamide (NMF) with adriamycin (ADM) on a human melanoma cell line (M14) were investigated. The results obtained can be summarized as follows: (i) When NMF was administered before ADM (NMF-->ADM), a decrease of ADM-induced cytotoxicity and intracellular ADM content was revealed. Conversely, the reverse combination (ADM-->NMF) produced a remarkable reduction of cell survival accompanied by a significant intracellular drug retention. (ii) The fluorescence microscopy revealed that in NMF- and in NMF-->ADM-treated cells the actin microfilament distribution appeared to be very similar to that in control cells. On the contrary, a disorganization of the microfilament architecture was observed in ADM-->NMF-treated cells. (iii) The microtubule organization was significantly altered by NMF. This effect appeared to be even more evident in M14 cells treated with the combination ADM-->NMF. (iv) Confocal microscopy observations showed an intracytoplasmic retention of ADM in ADM-->NMF-treated cells. These findings suggest that the cytoskeletal changes induced by NMF might interfere with the ADM efflux mechanisms, accounting for the high drug level and low survival detected in ADM-->NMF-treated cells.

N-methylformamide as a potential therapeutic approach in colon cancer

PURPOSE

The effect of N-methylformamide, used in combination with the antineoplastic drugs adriamycin and cisplatin, on the cell survival of a colon carcinoma cell line (HT-29) was investigated. To better understand the mechanism involved in N-methylformamide-mediated chemosensitization, we evaluated the N-methylformamide effect on cell volume and surface expression of some integrins molecules (VLA2, VLA5, and VLA6) of the HT-29 cell line.

METHODS

The cell survival was evaluated by clonogenic assay; integrins surface expression was analyzed by means of flow cytometry; cell volumes were determined using a Coulter Channalyzer.

RESULTS

A Noncytotoxic dose of N-methylformamide (170 mM) sensitizes the HT-29 cell line to the lethal activity of both adriamycin and cisplatin. The analysis of cell volume showed that N-methylformamide exposure induces an increase in cell volume. Flow cytometric analysis of VLA2, VLA5, and VLA6 receptors showed that N-methylformamide increases the expression of the three integrins by 30 to 40 percent.

CONCLUSION

The plasma membrane could constitute one of the N-methylformamide targets and might be involved in the differentiation and chemosensitizing effects caused by this agent. Moreover, N-methylformamide could improve colon cancer treatment when used in combination with antineoplastic drugs.

Expression of beta 1, beta 3, beta 4, and beta 5 integrins by human lung carcinoma cells of different histotypes

Structural and functional analyses of several integrin heterodimers were performed in non-small-cell lung cancer (NSCLC) and small cell lung cancer (SCLC) cell lines. The expression of beta 1, beta 3, beta 4, and beta 5 heterodimers was evaluated at protein and mRNA levels. By flow cytometry and immunoprecipitation experiments we demonstrate that NSCLC cells (A549 adenocarcinoma and DG 3 large cell carcinoma) coexpress integrin heterodimers composed of beta 1, beta 3, beta 4, and beta 5 subunits, whereas SCLC cells (AE2 and H69) express only beta 1 integrin heterodimers. Northern blot experiments confirmed immunochemical analysis: SCLC cells in contrast to NSCLC cells express only the mRNA coding for the beta 1 subunit. These data indicate that in lung carcinoma cells the diversity in the integrin repertoire depends upon differential gene expression. The functionality of integrin receptors has been studied using antibody blocking experiments. Data reported demonstrate that the alpha 6 beta 1 integrin is a laminin receptor in either SCLC or NSCLC cells. An antibody to the beta 4 subunit partially inhibits the adhesion of adenocarcinoma cells to lamin but does not block lamin adhesion of large cell carcinoma cells, even though alpha 6 beta 4 complexes are expressed on both cell types. Two antisera to vitronectin receptors inhibit the adhesion of NSCLC cels to both vitronectin and fibronectin. The same antisera inhibit the adhesion of SCLC cells only to laminin, indicating that the alpha v beta 1 integrin might function in these cells as laminin receptor.

Inhibition of c-fes expression by an antisense oligomer causes apoptosis of HL60 cells induced to granulocytic differentiation

The c-fes protooncogene is expressed at high levels in the terminal stages of granulocytic differentiation, but so far no definite function has been attributed to the product of this oncogene. To tackle this problem, the c-fes protooncogene expression has been inhibited in HL60 cells, and fresh leukemic promyelocytes of acute promyelocytic leukemia have been induced to differentiate with retinoic acid (RA) and dimethylsulfoxide (DMSO). Inhibition was obtained by incubating the cells with a specific c-fes antisense oligodeoxynucleotide. It was observed that the cells, rather than differentiating, underwent premature cell death showing the morphological and molecular characteristics of apoptosis. This process was inhibited by granulocyte and granulocyte/macrophage colony-stimulating factor, but not by interleukin 3 (IL-3), IL-6, or stem cell factor. Our present results demonstrate that the loss of cell viability that occurs during the in vitro differentiation of myeloid cells, after the complete inhibition of the c-fes gene product and treatment with RA-DMSO, is due to activation of programmed cell death. It is concluded that a possible role of the c-fes gene product is to exert an antiapoptotic effect during granulocytic differentiation.

Flow cytometric analysis of ploidy in colorectal cancer: a multicentric experience

Ploidy and cell proliferation determined by flow cytometry were assessed on colorectal cancers from patients admitted to two Italian cancer research centres. A total of 181 patients were followed prospectively for 4 years at the Istituto Regina Elena (IRE) of Rome and at the Istituto Nazionale Tumori (INT) of Milan. Fresh (at the IRE) or frozen (at the INT) tumour material and similar procedures were used for subsequent sample preparation. Similar frequencies of aneuploid tumours (63% vs 66%) and superimposable median DNA indices (1.6) were observed for the two case series. In both series, DNA ploidy was generally unrelated to clinico-pathological factors, except for a higher frequency of aneuploid tumours in Dukes' D (88%) than in Dukes' A stage (33%) in the IRE experience. DNA ploidy was a weak prognostic indicator at 3 years but not at 4 years in the IRE case series, and it never exhibited a clinical relevance in the INT experience. Conversely, multiploidy was an indicator of worse relapse-free and overall survival at 4 years in the IRE and INT case series.

Flow cytometric analysis of DNA content and cell kinetics in colorectal carcinoma

DNA ploidy and cell proliferation were studied by means of flow cytometry in 98 patients with primary colorectal adenocarcinoma. Multiple samples of tumour burden were pooled and freshly dissociated immediately after surgery for FACS analysis. The relationships between ploidy, proliferative activity, evaluated in terms of S-phase percentages (%S), and some clinico-pathological variables were analyzed. 87 of the 98 tumors yielded evaluable DNA histograms: 32 were diploid (37%) and 55 were aneuploid (63%; median DNA index = 1.6). Multiple aneuploid cell populations were found in 15 tumors (17%). The % S was estimated by means of a mathematical model. Aneuploid tumors showed % S values significantly higher than diploid ones (p < 0.0001). Differences in the distribution of DNA aneuploidy were observed in relation to Dukes' stage and tumor site, left colon, rectum and stage D tumors being more frequently aneuploid. No significant differences in proliferative activity were observed in relation to most of the clinical variables, except for higher % S values observed in tumors of right colon compared to those of left colon and rectum.

Sample preparation for bivariate flow cytometric analysis of breast tumor specimens

The availability of monoclonal antibodies (MAbs) raised against functional or phenotypic cell markers can improve the suitability of flow cytometry (FCM) in assessing and validating prognostic parameters of human neoplasia. The major problems encountered in this type of study, when performed on solid tumors, are the recovery of a large and representative number of tumor cells and the possibility of performing a DNA analysis on antigen-selected populations. A panel of MAbs was chosen on the basis of the recognized membrane antigens important to the biologic characterization of human breast cancer cell populations. The possibility of performing bivariate FCM analysis of cell surface antigens and DNA content was investigated on 4 breast tumor cell lines and 10 fresh breast biopsies. Different fixations and tumor disaggregation procedures were considered. The results indicate that ethanol fixation is the most effective procedure for performing biparametric FCM analysis and that a combined enzymatic-mechanical disaggregation procedure applied on breast tumor specimens allows great recovery of intact cells without affecting antigen detection or DNA distribution.

Recombinant tumor necrosis factor for superficial bladder tumors

Twenty patients with histologically documented superficial bladder cancer (Ta, T1, Tis) were treated with intravesical administration of TNF 400-1800 micrograms. Of 18 patients with a marker lesion, 2 obtained a complete response for 8+ and 18 months. Two had a partial response and were given other intravesical therapies after 5 and 7 months. No or minimal systemic absorption of TNF was observed and documented in 4 of 20 patients by pharmacokinetic studies, and no patients developed antibodies to intravesically administered TNF. TNF was well tolerated in doses up to 1800 micrograms. No systemic or local side effects were observed. Modest activity was attained with intravesical TNF, even in pretreated patients.

Inhibition of leukemia cell proliferation by receptor-mediated uptake of c-myb antisense oligodeoxynucleotides

Exposure of human leukemia HL-60 cells to an oligodeoxynucleotide complementary to an 18-base sequence (codons 2-7) of c-myb-encoded mRNA has previously been shown to result in inhibition of cell proliferation. Because HL-60 cells express high levels of transferrin receptor we adapted a DNA delivery system based on receptor-mediated endocytosis to introduce myb oligomers complexed with a transferrin-polylysine conjugate into those cells. A DNA.RNA duplex resistant to S1 nuclease digestion was detected as early as 12 hr after culture of HL-60 cells in the presence of the myb antisense/transferrin-polylysine complex. Exposure of HL-60 cells to the myb antisense/transferrin-polylysine complex resulted in rapid and profound inhibition of proliferation and loss of cell viability much more pronounced than that occurring in cells exposed to free myb antisense oligodeoxynucleotides. The transferrin-polylysine/myb sense complex or the transferrin-polylysine conjugate alone had no effect on HL-60 cell proliferation and viability. These findings indicate that myb synthetic oligodeoxynucleotides enter efficiently into HL-60 by transferrin receptor-mediated endocytosis and exert a profound biological effect. Such a delivery system could exploit other ligand-receptor interactions for the selective delivery of oncogene-targeted antisense oligodeoxynucleotides.

N-methylformamide effects on cell proliferation and antigenic pattern in HT-29 colon carcinoma cell line

The effects of the differentiating agent N-methylformamide (NMF) on cell proliferation and antigenic pattern of HT-29 colon carcinoma cells have been investigated. The cell line was cultured in the presence, or absence, of 1% NMF and tested for the above mentioned characteristics, both in vitro and after injection into nude mice. The percentage of cells in the various cell cycle compartments was estimated by flow cytometry. The presentation on the cell surface of molecules such as tumour associated antigens (TAAs), HLA class I molecules and epidermal growth factor receptor (EGF-R) was analysed by ELISA, flow cytometry and immunohistochemistry. Results demonstrate that NMF impairs HT-29 cell proliferation with a remarkable accumulation in the G0/G1 phases, as well as inducing a modification of the membrane antigenic pattern. The presence of NMF in the culture medium decreases the TAAs and EGF-R whereas HLA antigen maintains the same level of positivity in the two cell lines. These alterations are consistent with a different behaviour in vivo of the tumours originated from NMF treated and untreated cells. Tumours derived from NMF treated cells show a delay in the appearance and low levels of immunodetectable carcinoembryonic antigen (CEA) molecules.

Characterisation of a human glioblastoma cell line (LI) expressing hypothalamic and pituitary hormones

The human glioblastoma cell line LI showed morphological features typical of its neuroectodermal origin. Cells were positive by immunofluorescence to GFAP, MHC class II, and L1 determinants. Cytogenetic analysis showed the presence of a modal chromosome number of 63, ranging from 58 to 69 chromosomes (DNA index was 1.6). Northern blot analysis demonstrated the presence of mRNA transcripts specific for transglutaminase C (type II or "tissue"), growth-hormone releasing-hormone (GHRH), insulin-like growth factor II (IGF-II), and proopiomelanocortin (POMC). The GHRH mRNA was present in two different sizes, one similar to the normal hypothalamic species of 0.75 kb, whilst the second species was a large transcript of approximately 10 kb size. Treatment with 5 microM retinoic acid or 5 mM alpha-difluoromethylornithine for 5 days sharply reduced the growth rate and also induced modulation of the ultrastructure and antigenic profile. This cell line may be useful to study glial differentiation and the relationship of GHRH, IGF-II and POMC expression with differentiation in neuroectodermal tumours.

Pharmacological purging of syngeneic bone marrow ex vivo: effect of treatment with doxorubicin and lonidamine on normal and leukaemic cells of DBA/2 mice

The in vivo effect of in vitro treatment with doxorubicin plus lonidamine on normal and leukaemic cells was investigated in a mouse model of syngeneic bone marrow transplantation. Different numbers of L5178Y tumour cells or normal bone marrow cells alone, or mixtures of bone marrow and leukaemic cells were incubated with doxorubicin (0.25, 0.5, 0.75, 1 microgram/ml) and/or lonidamine (50 micrograms/ml) and reinfused in DBA/2 mice. Lonidamine potentiated the cytotoxic effect of doxorubicin dependent on doxorubicin dosage and tumour cell concentration. Survival after injection of 10(4) in vitro-treated tumour cells was 42% for doxorubicin 0.75 micrograms/ml alone versus 100% for the combination with lonidamine and 50% for doxorubicin 1 microgram/ml alone versus 100% combination. Reinfusion of normal bone marrow incubated with doxorubicin alone or in combination with lonidamine in lethally irradiated mice did not occur in 12-14% of mice injected, indicating that the repopulating ability of stem cells was spared. These data suggest the potential usefulness of lonidamine in ex vivo purging of bone marrow before autologous bone marrow transplants in haemopoietic malignancies.

Valinomycin-induced modulation of adriamycin resistance and cationic probe distribution in MCF-7 cell lines

In vitro restoration of adriamycin sensitivity in a resistant human breast tumor cell line was obtained by continuous exposure to nanomolar nontoxic valinomycin concentrations. Seven-day treatment with nanomolar valinomycin concentrations caused a slight increase of the signal of the cationic fluorescent cyanine probe DiOC5(3) but did not appreciably affect adriamycin incorporation in the cells. A marked increase of the DiOC5(3) signal was obtained in the presence of micromolar valinomycin concentrations, which were incompatible with the in vitro cellular growth.

Different effects of sequential combinations of N-methylformamide with 5-fluorouracil on human colon carcinoma cells growing in nude mice

The effects of the combination of N-methylformamide (NMF) with 5-fluorouracil (5-FU) on tumor growth and morphological features of human colon carcinoma cells (HT29) implanted in nude mice were assessed. Both agents were administered i.p. at tolerable doses: 5-FU at 19 mg/kg for 5 days and NMF at 200 mg/kg for 12 days. Four main schedules were tested: 5-FU alone, NMF alone, NMF followed by 5-FU and 5-FU followed by NMF. The last sequence was the most effective, as compared with the other treatment regimens. In particular, the 5-FU----NMF combination induced a tumor inhibition of about 75% at the end of the treatments (17th day) versus an inhibition of 23%-43% in the other schedules. Morphological observations, carried out by light and electron microscopy, indicated a possible relationship between the presence of structural changes and tumor growth inhibition. The results of this study renew interest in the use of NMF in sequential combination confirming sequence as a critical factor for the optimal combination of NMF and 5-FU.

Antigenic expression changes occurring in adriamycin resistant MCF-7 mammary carcinoma cells

The antigenic phenotypic repertoire of MCF-7 human breast carcinoma cell line variants that display different sensitivity to adriamycin (Adr) was analyzed using monoclonal antibodies (MoAbs) recognizing five different tumor associated antigens (TAAs) and the external domain of the epidermal growth factor receptor (EGF-R). ELISA and cytofluorimetry determinations were used and results indicate a diminished expression of one antigenic determinant of the carcinoembryonic antigen (CEA) molecule, the disappearance of all the other TAAs and the de novo expression of the EGF-R in the MCF-7 AdrR (IC50/Adr:10 uM). Treatment with recombinant alfa-Interferon (alfa-IFN) did not enhance antigenic expression in MCF-7 AdrR cells.

Importance of cell cycle perturbations on the effectiveness of N-methylformamide and anti-neoplastic drugs in combination

The effect of N-methylformamide (NMF) in combination with Adriamycin (ADM) and cis-diamminedichloroplatinum (DDP) on the cell survival and cell cycle kinetics of two human tumour lines was assessed: HT29 colon carcinoma and M14 melanoma cells were exposed to ADM and DDP alone or in combination with a non-cytotoxic dose of NMF, according to different schedules. The results demonstrate that NMF exposure sensitized both tumour cell lines to the lethal activity of ADM and DDP; however, reverse sequences had to be applied to reach an increase in the lethal activity of the two different drugs. The ADM-NMF combination determined a powerful decrease in the surviving fraction of the two cell lines when ADM was given as the first agent (ADM----NMF), while the reverse sequence did not increase the ADM cytotoxic effect. With respect to the DDP-NMF association, the sequence which accounted for a greater sensitizing effect was NMF administration followed by DDP treatment (NMF----DDP). This work demonstrates the importance of timing in combined treatments which involve NMF. A delay in cell proliferation elicited by NMF exposure could be responsible for the effectiveness of the combined treatment.

Integrin (alpha 6/beta 4) expression in human lung cancer as monitored by specific monoclonal antibodies

In this study, the expression of the alpha 6/beta 4 integrin complex was analyzed in human lung carcinomas both in vitro and in vivo, using two monoclonal antibodies which recognize the integrin subunits alpha 6 (Mab 135-13C) and beta 4 (Mab 439-9B). Immunoprecipitation patterns obtained from established human lung carcinoma cell lines demonstrated that the alpha 6 and the beta 4 subunits were differentially expressed in carcinomas of different types. The alpha 6 subunit was expressed in all the cell lines tested (squamous cell carcinoma A431, adenocarcinoma A549, large cell carcinoma DG3, and small cell carcinoma AE2). The beta 4 subunit was expressed in non-small cell cancer lines but was not detectable in the small cell cancer line tested. Using a quantitative two-site assay, we measured the concentration of the alpha 6/beta 4 integrin in matched biopsies from primary lung tumors and from normal lung. These studies confirmed that the complex was differentially expressed in non-small versus small cell lung cancers and that it was also detectable in lysates from normal lung at low levels. The highest levels of alpha 6/beta 4 were found in moderately differentiated squamous cell carcinomas. By immunohistochemistry, the beta 4 subunit was detectable in all the squamous cell carcinoma and adenocarcinomas tested (a total of 59), but not in 10 small cell cancers. The patterns of immunoreactivity were consistent with the expected distribution of membrane glycoproteins and, in some squamous cell carcinomas, were suggestive of the localization displayed by molecules involved in carcinoma-stroma interaction. Immunohistochemical staining indicated that beta 4 was also expressed in specific types of nonrespiratory pulmonary epithelial cells.

Enhancement of hyperthermic damage on M14 melanoma cells by liposome pretreatment

Exponentially growing human melanoma cells (M14 cell line) were pretreated with various amounts of dipalmitoylphosphatidylcholine-containing multilamellar liposomes and then exposed to heat treatment (42.5 degrees C). Cell damage produced by the treatments, given separately or in combination, was evaluated in terms of cell survival. Our results demonstrate that the cell survival at 37 degrees C was not affected by liposome concentrations up to 1000 nmol of phospholipid/2.5 x 10(6) cells, while liposome treatment of cells before heat exposure determined a marked damaging effect even at 100 nmol of phospholipid/2.5 x 10(6) cells. The mechanisms of liposome-cell interaction have been investigated by electron microscopy or by electron spin resonance measurements of spin-labeled membranes of intact cells. Evidence has been obtained that liposomal lipids are either taken up by M14 cells or become incorporated in the cell membrane. The present data suggest the possibility that liposome treatments per se could be of potential value as a therapeutic approach, by increasing the effect of heat therapy.

N-methylformamide affects spontaneous metastases of 3LL lines and increases natural killer activity of tumor-bearing mice

The antitumor activity of the polar solvent N-methylformamide (NMF) was evaluated on three lines derived from the Lewis lung carcinoma (3LL), endowed with different metastatic potential. Two administration schedules were tested, these being repeated regimens of NMF (200 mg/kg per dose) for 12 consecutive days, starting 24 h or 6-10 days after tumor implantation (early or late treatment, respectively). The results of the present work can be summarized as follows: (1) NMF regimens did not greatly affect tumor growth behavior of 3LL lines; conversely, they markedly influenced their spontaneous colonizing ability in the lungs, either by delaying early metastatic spread or by reducing the number and size of pulmonary metastases already implanted. (2) A significant increase of NK cell activity during and after early treatment with NMF was observed in the more-metastasizing lines, thus suggesting the possibility of an immunomodulating effect of NMF.