Digital morphonuclear analyses of sensitive versus resistant neoplastic cells to vinca-alkaloid, alkylating, and intercalating drugs

Chemosensitizing Effect of Cernumidine Extracted from Solanum cernuum on Bladder Cancer Cells in Vitro

Cernumidine (CER) is a guanidinic alkaloid isolated from Solanum cernuum leaves. In this work, we investigated the cytotoxicity, chemosensitizing effect of cernumidine to cisplatin (cDDP) and the possible mechanism of action of the combination on bladder cancer cells. Cernumidine showed cytotoxicity and could sensitize bladder cancer cells to cisplatin. The combination of CER+cDDP inhibited cell migration on T24 cells. CER+cDDP down-regulated MMP-2/9 and p-ERK1/2, while it increased EGFR activity corroborating the observed cell migration inhibition. Down-regulation of Bcl-2 and up-regulation pro-apoptotic Bax and further depletion of the mitochondrial membrane potential (ΔΨm) indicates that mitochondria play a central role in the combination treatment inducing the mitochondrial signaling pathway of apoptosis in T24 cells. Our data showed that the alkaloid cernumidine is worthy of further studies as a chemosensitizing agent to be used in complementary chemotherapy.

Prediction of radiosensitivity in human bladder cell lines using nuclear chromatin phenotype

BACKGROUND

Nuclear texture analysis measures phenotypic changes in chromatin distribution within a cell nucleus, while the alkaline Comet assay is a sensitive method for measuring the extent of DNA breakage in individual cells. The authors aim to use both methods to provide information about the sensitivity of cells to ionizing radiation.

METHODS

The alkaline Comet assay was performed on six human bladder carcinoma cell lines and one human urothelial cell line exposed to gamma-radiation doses from 0 to 10 Gy. Nuclear chromatin texture analysis of 40 features was then performed in the same cell lines exposed to 0, 2, and 6 Gy to explore if nuclear phenotype was related to radiation sensitivity.

RESULTS

Comet assay results demonstrated that the cell lines exhibited different levels of radiosensitivity and could be divided into a radiosensitive and a radioresistant group at >6 Gy. Using stepwise discriminant analysis, a subset of important nuclear texture features that best discriminated between sensitive and resistant cell lines were identified A classification function, defined using these features, correctly classified 81.75% of all cells into their radiosensitive or radioresistant groups based on their pretreatment chromatin phenotype. Posttreatment chromatin changes also varied between cell lines, with sensitive cell lines showing a relaxed chromatin conformation following radiation, whereas resistant cell lines exhibited chromatin condensation.

CONCLUSIONS

The authors conclude that the alkaline Comet assay and nuclear texture methodologies may prove to be valuable aids in predicting the response of tumor cells to radiotherapy.

The homocamptothecin BN 80915 is a highly potent orally active topoisomerase I poison

BN 80915, a lead compound of the homocamptothecin (hCPT) family, has entered clinical trials. BN 80915 is a difluoro-hCPT where the six-membered alpha-hydroxylactone ring of camptothecin (CPT) is replaced by a seven-membered beta-hydroxylactone ring. Preclinical data reported here show that in spite of the modification to the crucial E-ring of CPTs, BN 80915 retains topoisomerase I poisoning activity as shown in living HT29 cells as well as in cell-free assays, where BN 80915 always performs better than SN-38 or TPT. In antiproliferative assays BN 80915 is also very potent as evidenced by IC50s values consistently lower than those of SN38 in sensitive cell lines as well as in their related multidrug-resistant lines overexpressing P-glycoprotein or multidrug resistance-associated protein. Furthermore, in human plasma, in contrast to CPT analogs, the hydrolysis of BN 80915 is slow, leading to improved plasma stability, and irreversible, thus avoiding toxicity related to the accumulation of active principle during excretion in the urinary tract. These findings may account for the good in vivo efficacy observed in PC3 xenograft experiments where BN 80915 administered orally at very low doses doubled the tumor growth delay in comparison to CPT-11 administered i.p. Altogether, these results strongly support further development of BN 80915.

Topoisomerase I-mediated antiproliferative activity of enantiomerically pure fluorinated homocamptothecins

Homocamptothecin (hCPT) is an E-ring modified camptothecin (CPT) analogue bearing a methylene spacer between the alcohol and carboxyl functions of the CPT lactone. Combining pronounced inhibitory activity of topoisomerase I (Topo I) with enhanced plasma stability, hCPT constitutes an attractive template for the elaboration of new anticancer agents. Fluorinated hCPT analogues, prepared in enantiomerically pure form, were assayed by their stimulation of Topo I-mediated DNA cleavage. Translation into cytotoxicity against tumor cells was evaluated on HT29 human colon adenocarcinoma and on the multidrug resistant lung and bladder tumor cell lines, A549 and T24r. Good correlation is observed between the ability of the drugs to stimulate Topo I-mediated DNA cleavage and the respective 50% inhibitory concentrations (IC(50) values) of the HT29, A549, and T24r cell growth. Fluorine substitution in the A-ring of hCPT was found to have a pronounced influence on biological activity, providing several compounds which are up to 100-fold more potent than CPT in terms of IC(50). Among these, 10,11-difluoro-hCPT has been selected for further development.

Vinflunine (20',20'-difluoro-3',4'-dihydrovinorelbine), a novel Vinca alkaloid, which participates in P-glycoprotein (Pgp)-mediated multidrug resistance in vivo and in vitro

Vinflunine (VFL) is a novel derivative of vinorelbine (NVB, Navelbine), which has shown markedly superior antitumor activity to NVB, in various experimental animal models. To establish whether this new Vinca alkaloid participates in P-glycoprotein (Pgp)-mediated multidrug resistance (MDR), VFL-resistant murine P388 cells (P388/VFL) were established in vivo and used in conjunction with the well established MDR P388/ADR subline, to define the in vivo resistance profile for VFL. P388/VFL cells proved cross-resistant to drugs implicated in MDR (other Vinca alkaloids, doxorubicin, etoposide), but not to campothecin or cisplatin and showed an increased expression of Pgp, without any detectable alterations in topoisomerase II or in glutathione metabolism. The P388/ADR cells proved cross-resistant to VFL both in vivo and in vitro, and this VFL resistance was efficiently modulated by verapamil in vitro. Cellular transport experiments with tritiated-VFL revealed differential uptake by P388 sensitive and P388/ADR resistant cells, comparable with data obtained using tritiated-NVB. In various in vitro models of human MDR tumor cells, whilst full sensitivity was retained in cells expressing alternative non-Pgp-mediated MDR mechanisms, cross resistance was identified in Pgp-overexpressing cells. Differences were, however, noted in terms of the drug resistance profiles relative to the other Vinca, with tumor cell lines proving generally least cross-resistant to VFL. Overall, these results suggest that VFL, like other Vinca alkaloids, participates in Pgp-mediated MDR, with tumor cells selected for resistance to VFL overexpressing Pgp, yet MDR tumor cell lines proved generally less cross resistant to VFL relative to the other Vinca alkaloids.

Lectin histochemistry of astrocytic tumors and in vitro characterization of lectin-induced modifications on the proliferation of the SW1088, U373 and U87 human astrocytic cell lines

The role of lectins as biosignalling molecules or as markers of human astrocytic tumors remains relatively unexplored. The aim of the present work is to investigate (1) whether or not human astrocytic tumors express specific glycans, evidenced experimentally by means of lectin histochemistry, and (2) whether, in turn, these lectins can significantly modulate astrocytic tumor cell proliferation. Using a cell image processor, we therefore began by quantitatively measuring the histochemical binding pattern of 5 lectins (WGA, PNA, PHA-L, GSA-IA4 and Con A) in 5 astrocytomas, 5 anaplastic astrocytomas and 5 glioblastomas. Secondly, we measured the influence of these 5 lectins on the proliferation of 3 astrocytic tumor cell lines (SW1088, U373 and U87) growing in vitro as monolayers. Cell proliferation was assessed by means of the colorimetric MTT assay. The histochemical lectin staining markedly varied intra- and inter-group. However, some constant results were obtained. Indeed, the staining increased markedly from GSA-IA4 and PHA-L through WGA and PNA to ConA in the three histopathological groups. The assessment of cell proliferation demonstrated that WGA, Con A and PHA-L very significantly decreased proliferation in the 3 astrocytic cell lines in a dose-dependent manner. Astrocytic tumor cells in the confluent growth phase were less sensitive to the WGA, Con A and PHA-L lectin-induced effects than cells in the log growth phase. The GSA-IA4 and PNA lectins had globally very weak effects on the proliferation of the astrocytic tumor cell lines. Increasing the fetal calf serum from 1% to 10% in the culture media significantly antagonized the WGA-, Con A- and PHA-L-induced cell proliferation decrease in the 3 astrocytic cell lines. In conclusion, the present data strongly suggest that some lectins (including WGA, Con A and PHA-L) significantly influence the proliferation of astrocytic tumor cells.

Dynamic characterization of glioblastoma cell motility

The cell motility dynamic of two glioblastoma cell lines (U373 and U87) was studied by means of an automatic video-cell-tracking-system enabling each cell in a colony to be tracked for several hours. Twenty-five experiments were performed on both models growing on three different supports (glass, plastic and Matrigel). Cell motility was significantly different in each cell line and also for different growth support in a given cell line. We observed that U87 cells are significantly (p < 0.00001) less motile than U373 cells. The most favorable growth supports for cell motility studies were Matrigel and glass. A significant (p < 0.001) correlation between cell colony density and cell motility was highlighted, with isolated cells exhibiting a motility level distinct from the one observed for colonies. The present methodology, which enabled cell motility to be quantified in human glioblastoma cells, represents an original tool for identifying new classes of compounds able to reduce glioblastoma cell motility and cell migration potential into the brain.

VIP and pituitary adenylate cyclase activating polypeptide (PACAP) have an antiproliferative effect on the T98G human glioblastoma cell line through interaction with VIP2 receptor

Functional VIP/PACAP receptors were identified in the human glioblastoma cell line T98G, based on the relative potency of VIP, PACAP and PACAP-38 to stimulate adenylate cyclase activity. Analysis of the T98G cells mRNA by reverse transcription followed by a polymerase chain reaction (RT-PCR) demonstrated the expression of the mRNA coding for the VIP2 receptor subclass only. VIP, PACAP-27 and PACAP-38 were potent and efficIent inhibitors of cell proliferation, assessed by the colorimetric MTT assay. VIP, PACAP-27 and PACAP-38 also reduced the incorporation of 3H-thymidine in T98G cells, but did not significantly alter the percentage of cells present at each stage of the cell cycle. Thus, VIP and PACAP, probably acting through a VIP2 receptor subtype, decreased cell proliferation.

Cross resistance and collateral sensitivity between cytotoxic drugs and radiation in two human bladder cell lines

The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) test was employed as a means of studying the cross resistance and collateral sensitivities of two bladder cell lines able to grow in the presence of several antineoplastic drugs and/or despite the effects of radiotherapy. This cross resistance and collateral sensitivities were investigated in the context of two antineoplastic drugs (i.e. doxorubicin (an anthracycline) and vinorelbine (a Vinca alkaloid) and radiotherapy. The results show that cell lines able to grow in the presence of anticancer drugs develop a significant degree of resistance to antineoplastic compounds and may also develop resistance to radiotherapy. On the other hand, most cell lines treated first with radiotherapy develop a significant degree of resistance towards ionizing radiation and may also display increased sensitivity towards anticancer drugs. If these results obtained in vitro are clinically relevant, they may have important applications in the treatment of patients. Nevertheless, it will be necessary to validate the results on extensive series of chemo- and/or radioresistant cell lines exhibiting different mechanisms of resistance.

In vitro characterization of prolactin-induced effects on proliferation in the neoplastic LNCaP, DU145, and PC3 models of the human prostate

BACKGROUND

Proliferation of normal and tumoral prostate tissue is regulated by androgens and various growth factors. We characterized the in vitro proliferative influence of prolactin (PRL) in androgen-sensitive and androgen-insensitive human prostate cancers.

METHODS

The biologic models employed included the androgen-sensitive LNCaP and the androgen-insensitive DU145 and PC3 cell lines. PRL-induced influences (0.1-10 mIU/ml of medium) on proliferation were assessed using the colorimetric methylthiotetrazole assay. Androgen sensitivity in the three cell lines was determined by assessing the proliferative influence of dihydrotestosterone (DHT) (0.1-10 nM). PRL-induced modifications in PC3 cell kinetics were assessed using Feulgen-stained nuclear image cytometry.

RESULTS

Although DHT markedly stimulated LNCaP proliferation, it had no proliferative effect on the DU145 and PC3 cell lines. By contrast, PRL significantly modulated the proliferation of the DU145 and PC3 lines, but exerted weak, if any, effect on the proliferation of the LNCaP cell line. PRL increased the percentage of PC3 proliferating cells (i.e., cells in the S/G2 phases of the cell cycle) at low doses (0.1 mIU/mL) and decreased this percentage at high doses (10 mIU/ml).

CONCLUSIONS

Proliferation of androgen-insensitive human prostate cell lines can be significantly modulated by prolactin.

Cytotoxicity, cell cycle kinetics and morphonuclear-induced effects of Vinca alkaloid anticancer agents

The effects of four Vinca alkaloids (vinblastine, vincristine, vindesine and vinorelbine) on three neoplastic cell lines (the MXT mouse mammary cell line and the T24 and J82 bladder cell lines) were studied at three biological levels, i.e. cell proliferation, cell cycle kinetics and morphonuclear characteristics. These effects were studied by means of digital cell image analysis on Feulgen-stained nuclei. The aim of the present work was to characterize the effects specifically induced by Vinca alkaloids as compared with those obtained previously with other pharmacological classes of anticancer drugs. The results show that Vinca alkaloids inhibit the cell proliferation of neoplastic cell lines at a concentration of 10(-8) M except in the case of the J82 cell line, for which only a slowing down of cell proliferation was observed. Concerning the cell cycle kinetics, the results show that the Vinca alkaloids induce an accumulation of cells in the mitosis phase. This accumulation of mitotic cells was maximal after 15 h incubation in the presence of the drugs. A study of the morphonuclear-induced effects of Vinca alkaloids showed that the variance of the optical density (VOD) is strongly influenced by these Vinca alkaloids. The development of the VOD was parallel with the development of the percentage of mitosis; thus, the VOD enabled the Vinca alkaloid-induced effects to be specifically characterized from a morphonuclear point of view. On the other hand, the results show that the mean value of the variance of the optical density was very highly correlated (P < 0.001) with the efficiency of the Vinca alkaloids in terms of cytotoxicity. In clinical studies, the analysis of the development of this parameter would make it possible to assess the response to chemotherapy in the case of patients treated with Vinca alkaloids.

Chemotherapy-induced nuclear alterations of morphologic and genomic characteristics in a human colon cancer grafted onto nude mice

PURPOSE

A human Dukes B colonic adenocarcinoma was grafted onto 40 nude mice. The mice were divided into four groups, one control and three representing experimental conditions. Animals in the three experimental groups received either adriamycin (ADR), 5-fluorouracil (5-FU), or camptothecin (CPT) over a 25-day period beginning 34 days after grafting. Control animals received saline on an identical schedule. Animals were killed 105 days after grafting.

METHODS

The effect of therapy was assessed by three techniques: 1) tumor size was periodically measured during the life of the animals, 2) modifications of APC, Ki-ras, and p53 genes were studied by polymerase chain reaction, dot-blot analysis, restriction analysis, and DNA sequencing, and 3) image cytometry of Feulgen-stained material was used to characterize 15 parameters describing morphometric, densitometric, and textural features of tumor nuclei.

RESULTS

When compared with controls, tumor growth (size) was maximally suppressed by treatment with CPT (P < or = 0.001). Growth was inhibited significantly by treatment with 5-FU (P < or = 0.01); no statistical difference in tumor size was observed between controls and animals treated with ADR. Modifications of APC, Ki-ras, and p53 genes were not observed; however, treatment did inhibit amplification of APC and p53 genes.

CONCLUSIONS

The 15 morphonuclear parameters were assessed to define populations of cell nuclei altered by chemotherapy. Although CPT maximally suppressed growth, it did not alter nuclear morphology when compared with controls. Treatment with either 5-FU or ADR resulted in nuclear morphologic alterations defined as distinct populations using multivariate analysis. Nonsupervised linear discriminant analysis was used to quantify the relative proportions of these populations. Four morphonuclear parameters were identified, which discriminated nuclei exposed to either ADR or 5-FU from controls.

Comparative study of multidrug resistance evaluated by means of the quantitative immunohistochemical detection of P-glycoprotein and the functional release of rhodamine 123

The immunological detection of P-Glycoprotein (P-GP) and the functional release of Rhodamine 123 (R123) have been compared in a number of human and murine cancer cell lines, in chemo- and/or radiotherapy-resistant subclones, and in clinical specimens from patients. The chemoresistance level was established from the viability index (IC50) in the presence of doxorubicin. Cytocentrifuge preparations were immunostained with JSB-1 monoclonal antibody followed by the alkaline phosphatase anti-alkaline phosphatase technique. The strength of the reaction was quantified by a digital image analyser. The kinetic incorporation and release of Rhodamine 123 were evaluated by flow cytometry. The parent cell lines and radiotherapy resistant subclones showed a low IC50, were JSB-1 negative and retained R123 during the whole experiment, while the chemoresistant and radio-chemoresistant cell line mutants had a high IC50, were JSB-1 positive, and actively pumped the R123 out of the cells. Good correlations were obtained between the IC50, the digital image analysis, and flow cytometry. The kinetic profile of the R123 release allowed the distinction between typical and atypical multidrug resistance phenotypes. These findings were confirmed in clinical specimens from patients. We conclude that antigenic and functional studies are complementary and are useful in experimental and clinical approaches to multidrug resistance.

Computer-assisted morphonuclear characterization of radiotherapy-induced effects in MXT mouse mammary adenocarcinomas surviving earlier radiotherapy

PURPOSE

To present the effects of different radiotherapeutic treatments on the morphonuclear characteristics and growth of the MXT mouse mammary adenocarcinoma.

METHODS AND MATERIALS

We collected MXT tumor cells by means of fine-needle aspirations during various radiotherapeutic treatments and analyzed the morphological aspects of the cell nuclei by means of the digital cell image analysis of Feulgen-stained nuclei. In addition, we studied the morphonuclear aspects of cells from MXT tumors that had been radioresistant cell enriched. These radioresistant cell-enriched tumors involved MXT tumors that had survived one or two previous radiotherapies. The radiotherapy-induced effects on the morphonuclear characteristics were monitored by means of both monovariate (one-way variance) and multivariate (principal components and step-wise linear discriminant) analyses.

RESULTS

The monovariate analyses showed that radiotherapy significantly influenced the values of the parameters relating to nuclear size (nuclear area--NA), the frequency of small dense chromatin clumps (short run length emphasis--SRL) in the nuclei, and the overall chromatin condensation level (local mean--LM). The global effect corresponded to a decrease in the overall chromatin condensation level in the radioresistant cell-enriched MXT tumors. This decrease occurred concomitantly with an increase in the frequency of the small dense chromatin clumps in the nuclei and a decrease in the nuclear area. The multivariate analyses showed that it was possible to quantitate the proportion of "radiosensitive-like" and "radioresistant-like" cell nuclei in the various MXT tumor types under study.

CONCLUSIONS

The development of certain morphonuclear parameters, that is, the NA, the SRL, and the LM, could be proposed to predict the response of human tumors to radiotherapy as, indeed, could the quantitation of the proportion of radioresistant cells.

P-glycoprotein mediated resistance to 5'-nor-anhydro-vinblastine (Navelbine)

Navelbine (NVB, vinorelbine tartrate) is a semisynthetic Vinca alkaloid in which the catharanthine moiety contains an eight-membered ring in place of the nine-membered ring that is present in all naturally occurring members of the vinblastine group. This modification selectively reduces interaction with anoxal vs mititotic microtubules and may account for the lower neurotoxicity with improved antitumor activity that has been observed in clinical trials with breast, lung and ovarian cancer. We were interested in whether the structural modification in NVB would also alter the drug resistance profile. Specifically, our aim was to determine whether NVB, like vinblastine (VBL), participates in P-glycoprotein (P-gp)-mediated multidrug resistance (MDR). NVB-resistant, murine P388 cells (P388/NVB), were derived in vivo and used in conjunction with a battery of drug-resistant P388 cell lines in vivo and murine and human tumor cell lines in vitro to develop a resistance profile for NVB. P388/NVB bells were cross-resistant to drugs involved in MDR (doxorubicin, etoposide, amsacrine, vinblastine, vincristine and actinomycin D), but not to the alkylating agents, cyclophosphamide, carmustine, and cisplatin, or to the antimetabolites, 5-fluorouracil and methotrexate. P388/NVB cellular resistance to NVB was stable without drug pressure during continuous passage in vivo for more than ten weeks and in vitro for at least five weeks. These cells exhibited increased expression of P-gp, and a 30-fold level of resistance of NVB in vitro, which was completely reversable with verapamil. The MDR phenotype was confirmed in other tumor models. P388 tumors resistant to vinblastine, vincristine, doxorubicin, and etoposide were cross-resistant to NVB in vivo.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of chemotherapy-induced morphonuclear modifications in the P388 leukaemia and the MXT mammary tumour models of the mouse

Chemotherapy-induced morphonuclear modifications were monitored in vivo by means of the digital cell image analysis of Feulgen-stained nuclei. Two experimental models were used, i.e. the P388 mouse leukaemia and the MXT mouse mammary carcinoma. The drugs used were doxorubicin, etoposide and cyclophosphamide. The results indicate that the chemotherapy induced a significant decrease in the MXT tumour growth and a significant increase in the survival of the P388 leukaemic mice. These effects were accompanied at the morphonuclear level by an increase in the nuclear area, by modifications in the DNA content in accordance with the effects of the drugs on the cell cycle and by several modifications in the chromatin texture in accordance with the model or the drugs studied. While there were neither homogeneous morphonuclear changes in all treatment groups nor clearcut correlations between the morphonuclear changes and tumour growth or the survival of the animals, the present study nevertheless shows that it is possible, at least partly, to monitor in vivo certain chemotherapy-induced effects occurring at the morphonuclear level, and subsequently to obtain information on the mode of action of the drugs.

Characterisation of the influence of anti-gastrin, anti-epidermal growth factor, anti-oestradiol, and anti-luteinising hormone releasing hormone antibodies on the proliferation of 27 cell lines from the gastrointestinal tract

Numerous data from published reports prove that the proliferation of gastrointestinal tumour cell lines are under the control of many hormones or growth factors, or both. Most of these publications report the influence on a very small number of cell lines of one or two such factors only. This work deals with the in vitro characterisation of the influence of the anti-gastrin, the anti-epidermal growth factor (EGF), the anti-oestradiol (E2), and the anti-luteinising hormone releasing hormone (LHRH) antibodies on the proliferation of a large series of gastrointestinal cell lines. Cell proliferation was assessed by means of the colorimetric MTT assay on a series of 27 gastrointestinal cell lines obtained from the American Type Culture Collection (ATCC). Of the 27 cell lines, the anti-gastrin, the anti-EGF, the anti-E2, and the anti-LHRH neutralising antibodies considerably influenced the proliferation of 13, 25, 12, and 16. No gastrointestinal cell line was unresponsive to the four antibodies simultaneously. The anti-gastrin and anti-EGF antibody induced effects on the 27 gastrointestinal cell line proliferation were significantly correlated, as was also the case for the anti-E2 and anti-LHRH antibody induced effects. Of the anti-gastrin, the anti-EGF, the anti-E2, and the anti-LHRH antibodies, it was the anti-EGF one that had the greatest influence, both quantitatively and qualitatively, on gastrointestinal cell proliferation. The correlation of the effects of definite anti-hormone antibodies is suggestive of a common mechanism of action for the corresponding hormones and casts some doubt on the efficiency of anti-hormone monotherapy.

Morphonuclear characterization of drug resistance by means of digital cell-image analysis: an in vitro assessment

The prediction of tumor resistance to antineoplastic drugs remains an important challenge in cancer chemotherapy. Several methods have been proposed in this connection, but they present a number of problems such as clinical relevance and applicability. In the present work we put forward an original methodology to assess the drug sensitivity of cancer cells. For this purpose we submitted chemosensitive and chemoresistant cell lines to different anticancer drugs and monitored the cell growth and the drug-induced morphonuclear effects by means of digital cell-image analysis of Feulgen-stained nuclei. The results showed that drug-induced effects at the morphonuclear level correlated statistically with the effects produced at the cell proliferation level. For example, the mean nuclear size value increased as a function of the drugs' efficiency recorded at the cell proliferation level. In the same way, the frequency of large dense chromatin clumps also increased in accordance with the drugs' efficiency. The present work thus demonstrates that digital cell-image analysis can be applied to monitor the efficiency of chemotherapeutic treatment carried out on cell lines in vitro. The present methodology could possibly be used on solid tumors, from which biological material can be obtained serially by means of fine-needle aspiration. As evidence of this, the present methodology can also be applied to hematological cancers.

Image cytometry determination of ploidy level, proliferative activity, and nuclear size in a series of 314 transitional bladder cell carcinomas

Image cytometry was carried out on 281 superficial (Ta and T1) and 33 invasive (T2 to T4) bladder cancers. The parameters used to characterize these bladder tumors were: (1) histopathological grading, (2) clinical staging, (3) tumor size, (4) deoxyribonucleic acid (DNA) index (DI), (5) DNA histogram type (DHT), (6) percentage of euploid (diploid plus tetraploid) cells, (7) percentage of polyploid cells (> 5C DNA content), (8) proliferative activity (S phase fraction value), and (9) nuclear area (NA). The proliferative activity of the tumors was not related to either histopathological grade or to clinical stage, but it was related to the DHT parameter, which made it possible to identify diploid, hyperdiploid, triploid, hypertriploid, tetraploid, and polymorphic tumors. The hypertriploid tumors exhibited a significantly lower proliferative activity than the nonhypertriploid ones. Although both the DI and the NA values correlated significantly with histopathological grading, only the NA values correlated significantly with clinical staging. We further observed that some grade III bladder tumors were definitely diploid, whereas some grade I tumors were highly aneuploid. We thus hypothesize that the ploidy level of a given tumor reflects its age directly and its aggressiveness only very indirectly. In our opinion aneuploidy is only an indirect marker of aggressiveness because it reflects the fact that a malignant tumor is old, ie, has been present in a patient over a long period of time and has had ample time to express its malignancy at the clinical level. A significant relationship was accordingly obtained between tumor size and ploidy level with the highest proportion of aneuploid tumors and the highest percentage of polyploid cell nuclei being observed among the largest bladder tumors.

Effects of castration and testosterone on Fel dI production by sebaceous glands of male cats: II--Morphometric assessment

A morphometric study of cat sebaceous glands was performed to evaluate the effects of castration and testosterone treatments. Skin biopsies were taken in six cats before castration, after castration and after the testosterone injections administered after castration (total number of biopsies: 18). Ninety 8 microns thick sections of each biopsy were assessed for image analysis processing (SAMBA 2005, ALCATEL TITN). The variations in glands and cells size were evaluated on digitized microscopic images by morphometric parameters included in the SAMBA software package. An original software was developed for the analysis of the spacial gland structure. The best morphometric parameters were selected in a first step of the study, and included the nuclear surface (NS), the cell surface (CS) and the nuclear/cellular surface ratio (N/C). These three parameters were then compared in each group of samples for the six cats. It was shown that after castration the N/C (21%) significantly increased compared with prior to castration (12.6%). This 59.8% increase was mainly due to cell cytoplasm shrinking reflecting a decrease of the cell activity. The testosterone administered after castration produced a reverse effect with a N/C ratio back to normal (11.4%) and a significant cell cytoplasm and gland enlargement as shown by the three dimension constructions. This morphometric data correlated with the measurement of sebum and Fel dI productions. The negative effects of castration and the positive effects of testosterone on the sebaceous cells and glands volume favour the hypothesis that cat sebaceous cells are subject to hormonal control this is also likely to apply to the Fel dI production.

Characterisation of a navelbine-resistant bladder carcinoma cell line cross-resistant to taxoids

A bladder carcinoma cell line (J82) was selected for resistance to the new vinca alkaloid navelbine. The resistance factor of the resistant subline (J82-NVB) to navelbine was 17. P-glycoprotein was not detected in the membrane of J82-NVB cells. The lack of cross-resistance to multidrug-resistant (MDR) drugs such as doxorubicin, epipodophyllotoxins and colchicine, the absence of increase in navelbine efflux and the fact that a reduced accumulation of the drug cannot account for the resistance level confirmed that the phenotype of resistance of J82-NVB cells is not a classical MDR phenotype. Moreover, verapamil did not reverse the resistance of J82-NVB cells. The cells were cross-resistant to vinca alkaloids and taxoids which share the same target protein: tubulin. Analysis of microtubules using immunofluorescence showed that disassembly of the microtubular network occurred for the same concentration of navelbine in sensitive and resistant cells. However, after treatment with a concentration of navelbine inducing depolymerisation in both sensitive and resistant cells, reassembly of the microtubular network was observed only in resistant cells. This study suggests that the mechanism of resistance of J82-NVB cells involves recovery from the inhibition of microtubule dynamics induced by drug treatment.

Influence of culture media on the morphological differentiation of the PC-3 and DU145 prostatic neoplastic cell lines

The concept of differentiation of prostate cancer in terms of morphonuclear characteristics and population dynamics was investigated on the PC-3 and DU145 cell lines. A software based on the concept of Voronoi paving was set up in order to characterize the structure of these cell lines growing in vitro on histological slides. The morphonuclear characteristics were assessed by means of the digital cell image analyses of Feulgen-stained nuclei. The in vitro "morphonuclear" and "pseudo-tissular" differentiations of the PC-3 and DU145 cells were described in terms of the use of various culture media, i.e., media supplemented with either 10% (F10 medium) or 1% (F1 medium) fetal calf serum and with (or without) platelet-derived growth factor and dihydrotestosterone (PA10 and PA1 media). The present data reveal that the PC-3 cell line would be more hormone-sensitive than the DU145 one. Indeed, decreasing the FCS concentration in the culture medium while adding DHT and PDGF led to marked modifications to the morphonuclear characteristics of the PC-3 cells, but not to the DU145 cells. These modifications corresponded to an increase in nuclear size occurring concomitantly with chromatin decondensation. In the same way, spectacular modifications in terms of medium-induced pseudo-tissular differentiation were observed in the PC-3 cell line, but not in the DU145 one. Such modifications corresponded to an increase in clone size related to an increase in the mean distances between neighboring cell nuclei in a given clone. Thus, according to the criteria defined in this study, the PC-3 cell line would seem to maintain a higher degree of differentiation than the DU145 cell line.

Characterization of the differentiation of human colorectal cancer cell lines by means of Voronoi diagrams

This paper describes differentiation in terms of population dynamics through the medium of Voronoi paving which enables (via digital cell image analysis) the structure of human LOVO and HCT-15 colorectal neoplastic cell colonies growing on histological slides to be characterized. Two other tests were also used, i.e., the colorimetric MTT assay that enables the cell growth level to be determined, and a test allowing the assessment of the proliferation index, i.e., the percentage of cells in the S phase of the cell cycle. The results show that these colorectal neoplastic cells exhibited a comparatively high level of organisation in terms of the topographical distribution of nuclei within the clones when the cells were cultivated in media containing even small amounts of fetal calf serum. On the other hand, certain chemically defined media completely overturned this "pseudo-tissular" architecture. Furthermore, the colorectal cells growing in media including fetal calf serum exhibited relatively large and dense clones, undergoing an increase in the density of these clones when hormones were added to the culture medium and, concomitantly, a decrease in their proliferation. In contrast, the cells growing in chemically defined media generally exhibited smaller clones whose cell proliferation was paradoxically greater than that of the cells referred to above. This seems to bring out the importance of the part played by the cell loss factor in this cell population dynamic.

In vitro characterization of radiotherapy-induced morphonuclear modifications on chemosensitive as opposed to chemoresistant neoplastic cells

PURPOSE

We describe by means of digital cell image analysis the influence of X-ray radiation on three in vitro cultured cell lines for which we set up chemosensitive and chemoresistant variants.

METHODS AND MATERIALS

The three cell lines correspond to the MXT mouse mammary and the T24 and J82 neoplastic human bladder cells. The digital cell image analysis was carried out by computing morphometric (nuclear size), densitometric (proportion of cells in the G2 cell cycle phase), and textural features (chromatin pattern characteristics) on Feulgen-stained nuclei.

RESULTS

The results show that such digital cell image analyses make it possible to monitor radiotherapy-induced effects on these morphonuclear characteristics accurately. X-ray radiotherapy induces a dose-dependent increase in the proportion of cells in the G2 phase of the cell cycle along with a decrease in the overall chromatin condensation level. These two concomitant phenomena lead to a marked radiotherapy-induced increase in nuclear size. We also observed that radiotherapy-induced effects at the morphonuclear level are not only highly specific to the cell type analyzed, that is MXT mouse mammary or J82 or T24 human bladder carcinoma cells, but also to the fact that the cells are either chemosensitive or chemoresistant.

CONCLUSION

The digital cell image analyses of Feulgen-stained nuclei is helpful in monitoring the irradiation-induced morphonuclear modifications.

Monitoring of chemotherapy-induced morphonuclear modifications by means of digital cell-image analysis

We illustrate the potential application of digital cell-image analysis to characterize the morphonuclear modifications induced by various drugs including VP16, a podophyllotoxin derivative, PE1001, an investigational alkylating agent, and doxorubicin, an intercalating agent. Fifteen parameters representative of morphometric (nuclear area), densitometric (nuclear DNA content), and textural (chromatin organization, condensation, and distribution) features were computed on Feulgen-stained nuclei obtained from fine-needle aspirations serially performed during treatment on the MXT mouse mammary cancer model. We observed marked differences between the control and drug-treated MXT cell nuclei. However, mathematical data processing was necessary to improve the ratio of the chemotherapy-induced morphonuclear signal to the control biological morphonuclear signal. This data processing relies upon the use of principal-component analysis followed by the canonical transformation of data. The present method can be applied to all human cancers on which fine-needle aspiration can be performed.

Digital cell image analysis of verapamil-induced effects in chemosensitive and chemoresistant neoplastic cell lines

We used chemosensitive and chemoresistant variants of the neoplastic mouse MXT mammary and human J82 and T24 bladder cell lines to characterize verapamil-induced cell proliferation and morphonuclear modifications in drug-treated and untreated cells. Chemoresistance to vinorelbine (Navelbine, a Vinca alkaloid derivative), to DIAM3 (an investigational alkylating compound) and to Adriamycin (an intercalating agent) in the presence or absence of verapamil was monitored by means of the colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The results showed that verapamil restored a significant level of chemosensitivity in doses such as 1 microM or 10 microM in the three chemoresistant variants. The digital cell image analysis of Feulgen-stained T24-resistant cell nuclei revealed that verapamil restored the drug-treated cell kinetics and morphonuclear features observed in the sensitive counterpart especially with respect to the effects of Adriamycin. Interestingly, verapamil induced a highly significant chromatin decondensation in resistant but not in sensitive variants. Such verapamil-induced decondensation may favour the accessibility of drugs to their DNA targets. Therefore, in addition to the well-known action of the drug on the influx of a cytotoxic compound from the cellular to the intracellular compartment, verapamil might also favour the accessibility of the nucleus, to the drug.

Chemotherapy for urothelial tract malignancies: breaking the deadlock

Chemotherapy treatments for urothelial tract tumors have improved to the point that some patients are enjoying long-term disease-free survival. Moreover, with currently available agents and combinations, and with our increased application of clinical and biologic prognostic factors, we are refining our ability to select appropriate therapies for individual patients. We have learned that once the decision is made to use combination chemotherapy, adequate doses should be used. This can be facilitated by the coadministration of hematopoeitic growth factors. Recently completed phase II trials have confirmed that higher doses and dose rates may increase response proportions of and in particular, the proportion of complete responses. The finding that granulocyte colony stimulating factor enhances the sensitivity of tumor cells to methotrexate in vitro and to other agents studied against urothelial tumors implanted in nude mice implies an expanded role for these compounds. However, because non-hematologic toxicities are still important, it is unlikely that simple escalation of all components a four drug regimen such as of M-VAC (cisplatin, methotrexate, vinblastine, and doxorubicin) will have a significant impact on survival. In addition, as more is learned about the pharmacokinetic and pharmacodynamic relationships of the active agents, it appears that better schedules can be designed to improve the therapeutic index of the compounds. Ultimately we will be able to determine drug sensitivities, both at the start of therapy and as it evolves during treatment, that will allow a better selection of a particular chemotherapeutic regimen. For example, mdr1 induction appears to play a significant role in the therapy for treatment-resistant tumors. The availability of a number of active salvage regimens that are not constrained by this mechanism hints that changes in drug sequencing and drug scheduling may provide a significant improvement in outcome. While established combination chemotherapy regimens should be considered standard therapy in appropriately selected patients, promising strategies and new agents need to be investigated if we are to "break the deadlock" that has appeared in the treatment of urothelial tumors. These investigations can be performed safely in a well-controlled fashion to enable the identification of new regimens and to compare promising strategies with appropriate control populations in randomized trials.

Evaluation of breast carcinoma chemosensitivity by flow cytometric DNA analysis and computer assisted image analysis

Flow cytometric (FCM) DNA and S-Phase (S%) analyses were compared to computerized image analysis (SAMBA 2005) in 27 breast carcinomas (T3, N0-N1, M0) treated by 3 cycles of preoperative Adriamycin, vincristine, cyclophosphamide, methotrexate, 5-fluorouracil (AVCMF) chemotherapy (CT). Twelve carcinomas had shown objective regression and 15 no regression. Samples studied were obtained by sequential fine-needle cytopunctures. Comparing DNA profiles obtained by both methods before and after the first cycle, it appears that tumors can be divided into 3 groups. In the first group (10 cases), no changes were observed after the first cycle of CT. These tumors before treatment had either single DNA peak without cells in S% and G2M or a major peak with a small S% and G2M peak. The second group (9 cases) showed some changes in DNA profiles with an increased G2M peak but no additional values; these tumors before treatment had a small S% and a G2M peak. In the third group (8 cases), before treatment, all were non-diploid with high S% and high G2M. After the first cycle, all showed obvious changes in DNA profiles with a decrease of the G0/G1 peak and an increased S% and G2M with dispersed additional values along the scale in (G2M) x 2 and (G2M) x 4 regions. When changes were compared to tumor regression in the 1st and 2nd groups, 1/10 and 3/9 cases, respectively, were evaluated as objective regression. In the third group, all had objective regression (p less than 0.001). In most cases, a good correlation was observed with both methods.(ABSTRACT TRUNCATED AT 250 WORDS)