Biomedical subjects

R Kiss

Publications and source records attributed to R Kiss.

297 records · Page 17Linked to original sources

PubMedDate not supplied

Evidence of a direct relationship between the increase in the in vitro passage number of human non-small-cell-lung cancer primocultures and their chemosensitivity.

A pharmacologically relevant modelling was attempted for screening of new molecules potentially active against non-small-cell lung cancers (NSCLCs). It was in this way that we investigated the in vivo chemosensitivity firstly of three human NSCLCs grafted onto nude mice, secondly of their in vitro primocultures, and thirdly of the A427 and the A549 long-term cell lines obtained from the ATCC. Furthermore, the spontaneous development of the degree of chemosensitivity of the primocultures over their successive in vitro passages was compared with the development of the chromatin texture of the cancer cells. This chromatin texture was studied by means of the digital cell image analysis of Feulgen-stained nuclei. Our current experiments show that human non-small-cell lung cancers grafted onto nude mice possess a high level of chemoresistance. Such chemoresistance is conserved in vitro when these NSCLCs are adapted to grow as primocultures. Then, after only some in vitro passaging, the NSCLC chemoresistance quickly moved towards a high level of chemosensitivity, with a degree of sensitivity wholly similar to what was observed with respect to the long-term human lung cultures obtained from the ATCC. This reversion of chemoresistance in the NSCLC primocultures towards chemosensitivity occurred along with a specific transformation of their chromatin patterns, i.e. a marked increase in the frequency of the small dense chromatin clumps within the nucleus and a decrease of the larger ones.

Animals↗

PubMedDate not supplied

Monitoring of morphonuclear characteristics of hormone-sensitive and insensitive HCT-15 and LOVO human colorectal cells by means of digital cell image analysis.

We recently set up in vitro several human colorectal neoplastic cell lines that we labelled hormone-sensitive (HS) in comparison with the original cell lines which appeared to be rather "hormone-insensitive" (HI). We describe here the cell proliferation rate and the morphonuclear characteristics of the HS and HI variants of the HCT-15 and LOVO human neoplastic colorectal cell lines which were cultured either in serum-supplemented or chemically-defined media. Morphonuclear characteristics were monitored by means of the digital cell image analyses of Feulgen-stained nuclei, while the proliferation activity of the various cell types was assessed by means of the tetrazolium-based compound (MTT) assay. The results show that it is possible to culture human LOVO and HCT-15 colorectal cells in chemically defined media. This said, growth in a chemically defined medium is difficult for these cells and is markedly less sustained than when they are cultured in serum-supplemented media. The transition of the culture from a serum-supplemented medium to a chemically defined one is accompanied by a very marked drop in cell proliferation and a number of profound changes in terms of morphonuclear characteristics. These changes basically involve chromatin decondensation, which occurs as the result of the drop in the number of large chromatin clumps in the nucleus.

Cell Differentiation↗

PubMedDate not supplied

Nuclear DNA content, proliferation index and nuclear size determination in normal and tumoral adrenal tissues, pheochromocytomas and metastases.

The diagnostic values of nuclear size, proliferation index and ploidy level were investigated in a series of 58 samples from adrenal glands, including 9 samples from normal adrenal glands, 18 adenomas, 3 carcinomas, 16 pheochromocytomas and 12 metastases. Nuclear assessments were computed on Feulgen-stained nuclei by means of a cell image processor. Ploidy level was assessed by means of both the DNA index and DNA histogram type. The results show that nuclear size and proliferation index do not allow any discrimination between these various histopathologic subgroups. The measurement of ploidy level made it possible to obtain helpful information about these various histopathologic groups. Indeed, all the normal cases (except one from a malignant kidney tissue) and all adenomas (except one) were diploid, while most (but not all) of the remaining cases, including carcinomas, pheochromocytomas and metastases, were aneuploid. Furthermore, with this measurement we were able to show that some tendencies appear across these histopathologic groups. Indeed, the metastases contained a high proportion of aneuploid cases, whereas pheochromocytomas were frequently tetraploid. The results also show that the assessment of ploidy level by means of the DNA histogram type is more accurate than with measurement of the DNA index.

Adrenal Gland Neoplasms↗

PubMedDate not supplied

Chemoresistant cell lines: morphonuclear characteristics and chemosensitivity development during long-term culture.

The aims of the present work were first to study the stability of the sensitivity and resistance of various cancer cell lines over the period of one year, and second to attempt to correlate the morphological aspects of the lines with the results obtained. To this end we used one mammary and two human vesical lines, each consisting of three different phenotypes: a primitive phenotype (the sensitive line); a phenotype able to proliferate in the presence of three antineoplastic agents (the resistant line); and a phenotype derived from the resistant line but cultivated in the absence of drugs for more than 50 passages. We studied the stability of these lines not only in terms of their chemosensitivity to drugs, but also from the point of view of the morphological characteristics of their nuclei as described by digital image analysis. The results obtained show that the resistant lines retained their resistance even after treatment by antineoplastic agents had been discontinued. However, in this latter case variations became noticeable in their sensitivity to drugs, variations which shifted the line towards either the sensitive or the resistant phenotype. Results obtained from image analysis show that, for each of the lines studied, the morphological aspects of the continuously treated resistant and sensitive lines were phenotype-specific. However, the resistant lines no longer cultivated in the presence of anti-cancer agents exhibited morphonuclear characteristics varying across those of the other two phenotypes. We attribute these variations to modifications in the quality of the serum used.

Adenocarcinoma↗

PubMedDate not supplied

DNA histogram typing in human seminomas.

Characterization of the nuclear DNA content (DNA index and DNA histogram type) was carried out in 9 normal testicular tissues and 21 seminomas. Proliferative activity was further determined in the seminomas. Nuclear DNA content was assessed by means of a cell image processor computing the integrated optical density on Feulgen-stained nuclei from formalin-fixed paraffin-embedded materials. The results indicated that the so-called normal testicular tissues exhibited DNA histograms where three cell nuclei populations emerged in varying proportions. These three cell nuclei populations corresponded to haploid, diploid and tetraploid cell nuclei respectively. In contrast, most of the seminomas exhibited monomorphic DNA histogram patterns with a predominance of GO-G1 cell nuclei in the range of the 3c-4c nuclear DNA content. Further studies will be necessary in order to determine whether the DNA histogram has a predictive prognostic value or could be considered as a grading index.

Adult↗

PubMedDate not supplied

In vitro estradiol-sensitivity characterization of the MCF-7, ZR-75, MDA-MB-231 and T47-D human breast neoplastic cell lines.

Even if it seems that everything has been said about the influence of estradiol on cell proliferation in human breast cancer cell lines such as MCF-7, T47-D, ZR-75 and MDA-MB-231, in this study of the possible autocrine and/or paracrine role of 17 beta estradiol (E2) on the proliferation of human breast cancer cell lines we nevertheless offer some complementary information in this field of research. We exogenously stimulated the cell lines by the addition to the culture media of E2 and the anti-E2 antibody. The latter neutralizes the effects of any endogenous E2. The cell proliferation was assessed by means of the MTT colorimetric test. We thus showed that the level of sensitivity of various breast cancer cell lines to estradiol in terms of cell proliferation depends on the experimental schedule chosen. Indeed, the addition of E2 to the culture media stimulated the growth of the the ZR-75 and T47-D cell lines conventionally described as estrogen-receptor positive (ER+). For the MCF-7 cell line and the conventionally described as estrogen-receptor negative (ER-) MDA-MB-231 cell line, this is not the case. In sharp contrast, the addition to the culture media of the antibody neutralizing the biophysical activity of E2 sharply decreased the proliferation rate of the four cell lines under study. So these four cell lines in fact seem to be estradiol-sensitive. Thus, those which do not react to the addition of estradiol might use E2 in an autocrine and/or paracrine manner.

Antibodies↗

PubMedDate not supplied

Influence of culture media and multidrug resistance on the wheat germ agglutinin (WGA) glycocytochemical expression of two human glioblastoma cell lines.

Over the last two decades, many studies carried out with the aid of lectins have firmly established that cell glycans usually change in the course of the normal processes of growth and development, as well as in pathological situations. We describe here the in vivo binding expression of wheat germ agglutinin (WGA) to the U87 and U373 human glioblastoma cell lines exposed to various culture media i.e., media supplemented with either 10% (FCS10) or 1% (FCS1) fetal calf serum with or without 10 n Mol/l 17 beta-oestradiol (E2). After exposure to chemotherapeutic agents, the resistant variants (CR) developed by the two cell lines were also investigated. The quantitative cytochemical assessment of WGA binding was assessed by means of a cell image processor, which was also used to determine ploidy level (on Feulgen-stained nuclei) by means of DNA histogram typing (DHT). Our results clearly demonstrate that when U373 cells are cultured with E2, this steroid can modify the expression of WGA binding, whereas U87 cells were unaffected. Similarly, lowering the FCS level enhanced the WGA binding of the U373 cell line. Multidrug-resistant cell variants were associated with both aneuploidy and a dramatic decrease in cytochemical WGA expression.

Analysis of Variance↗

PubMedDate not supplied

Difference in glycohistochemical lectin staining of collagen fibers in the corpora cavernosa of normal and impotent men.

The objectives of this study were to investigate the value of glycohistochemical staining with three lectin types specific to a particular glycan structure (Arachis hypogaea [PNA], Triticum vulgare [WGA], and concanavalin A [Con A]) as a method of defining possible changes in the collagen structure in the corpora cavernosa in potent and impotent men. The study group consisted of 4 normal potent men and 22 men with various etiologies of impotence. The quantitative histochemical measurements were performed by means of a cell image processor. Two variables for each of the three types of lectins were studied. These were the mean optical density (MOD), which relates to glycohistochemical staining intensity, and the labeling index (LI), which is positively related to the percentage of immunostaining. Only WGA staining made it possible to discriminate significantly between the normal and pathological groups under study. The two parameters (LI, MOD) were significantly higher in the case of WGA staining in the normal group (P = 0.004 and 0.013, respectively). In contrast, only the mean LI value, in the case of the psychogenic and venogenic patients, reached a level of statistical significance (P = 0.005 and 0.001, respectively), when it increased from PNA through WGA to Con A histochemical staining. The two variables (LI, MOD) changed markedly from PNA through WGA to Con A in the arteriogenic patients (P = 0.003 and P < 0.001, respectively). WGA is of diagnostic value in distinguishing between normal and abnormal collagen in the corpora cavernosa. The difference in the lectin staining of the other groups, particularly the arteriogenic group, may be attributed to alterations in the glycosylation of the procollagen that are probably due to changes in the partial pressure of oxygen (PO2) level, an important cofactor in normal glycosylation. WGA staining may therefore be used as a marker to distinguish true psychogenic patients from those with organic diseases. Moreover, it may be used as an additional parameter in selecting the best candidates for penile revascularization.

Adult↗

PubMedDate not supplied

In vitro characterisation of soft tissue tumor chemosensitivity.

BACKGROUND: The benefit of performing chemotherapy on soft tissue sarcomas remains controversial. The present study deals with the in vitro characterisation of the influence of 3 antitumoral agents on the growth of 8 sarcoma cell lines. MATERIALS AND METHODS: Cell growth was monitored by means of the MTT colorimetric assay, which was further validated by a direct cell counting method. The three drugs tested included doxorubicin (ADR), cisplatin (DDP) and dacarbazine (DTIC). ADR was tested at 10(-5) M, 10(-6) M and 10(-7) M; DDP at 10(-5) M, 10(-6) M and 10(-7) M; and DTIC at 10(-3) M, 10(-4) M and 10(-5) M. A combination of the three drugs was also tested in order to ascertain whether a synergistic effect on cell growth inhibition could be obtained. A potential antineoplastic agent-induced influence on cell growth was determined 3 days after the addition of the diverse drug(s) to the culture media. The cell concentration was specifically adapted to each cell line. The 8 cell lines included 3 leiomyosarcomas, 1 malignant mixed Müllerian tumour, 3 rhabdomyosarcomas and 1 fibrosarcoma. RESULTS: The results show that of the three drugs tested, ADR was the most efficient in terms of the level of cell growth inhibition obtained and the number of cell lines whose growth was significantly inhibited. Of the three drugs, the least active was DDP. A significant synergistic effect was observed when the three drugs were added together to the culture medium. This synergistic effect was evident at the lowest doses tested for each drug. Whatever the histopathological type, the 8 cell lines exhibited a wide range of response to chemotherapy. CONCLUSIONS: The present study shows that the inhibition induced by 10(-7) M ADR, 10(-7) M DDP and 10(-5) M DTIC on sarcoma cell line growth is significantly more efficient than if each agent is tested individually. The in vitro methodology used here fits in with clinical reality because it enables sarcoma cell heterogeneity to be taken into account.

Antineoplastic Agents↗