BARX2 induces cadherin 6 expression and is a functional suppressor of ovarian cancer progression

The human homeobox BARX2 is located at 11q24-q25, within a minimal region associated with frequent loss of heterozygosity and adverse survival in epithelial ovarian cancer. BARX2 is a transcription factor that regulates transcription of specific cell adhesion molecules in the mouse. We show that BARX2 and cadherin 6 are expressed in normal human ovarian surface epithelium. BARX2 and cadherin 6 both have significantly lower expression in a clinical sample of endometrioid and clear cell ovarian cancers, as compared with serous or mixed mesodermal tumors. In a series of ovarian cancer cell lines, BARX2 expression showed a significant direct correlation with cadherin 6 expression. In OAW42, an ovarian cancer cell line that does not endogenously express BARX2, in vitro transfection of human BARX2 cDNA induced cadherin 6 expression. Transfection of BARX2 into OAW42 inhibited Matrigel invasion, haptotactic cellular migration to a collagen IV signal, and adhesion to collagen IV-coated plates. Our data demonstrate that BARX2 is expressed in the ovarian surface epithelium and has functional suppressor properties in ovarian cancer cells.

Regulation and function of the extracellular matrix protein tenascin-C in ovarian cancer cell lines

The extracellular matrix glycoprotein tenascin-C (TN) is overexpressed in the stroma of malignant ovarian tumours particularly at the interface between epithelia and stroma leading to suggestions that it may be involved in the process of invasion (Wilson et al (1996) Br J Cancer 74: 999-1004). To define regulation of TN further and investigate its function in ovarian cancer, a range of cell line models were studied. Concentrations of secreted TN in media from cultures of ovarian fibroblast cell lines were at least 100-fold greater than from carcinoma cell lines. Evidence for paracrine regulation of TN secretion was obtained by co-culture of carcinoma cells with fibroblast cells wherein secretion into the media was greater than from fibroblasts alone. Transforming growth factor (TGF)-beta1, insulin-like growth factor (IGF)-II and progesterone all stimulated TN secretion while human choriogonadotropin (hCG), follicle-stimulating hormone (FSH) and gamma-interferon inhibited secretion. TGF-beta1 produced the greatest stimulation of TN in cultured fibroblasts and its co-expression with TN was examined in primary ovarian tumours. There was a significant association between the presence of moderate-strong expression of TN and TGF-beta1. Evidence for TN having a functional role in ovarian carcinoma was obtained from adhesion and migration assays. The PE01, PE04, SKOV-3 and 59M cell lines all demonstrated marked adhesion to plastic coated with TN relative to the control protein bovine serum albumin (BSA) and expressed alpha2beta1 and alpha3beta1 integrins. The SKOV-3 cell line migrated more rapidly through TN than through BSA indicating that TN can facilitate migration of ovarian carcinoma cells.

Inhibition of transforming growth factor alpha (TGF-alpha)-mediated growth effects in ovarian cancer cell lines by a tyrosine kinase inhibitor ZM 252868

The modulating effects of the epidermal growth factor (EGF) receptor-specific tyrosine kinase inhibitor ZM 252868 on cell growth and signalling have been evaluated in four ovarian carcinoma cell lines PE01, PE04, SKOV-3 and PE01CDDP. Transforming growth factor alpha (TGF-alpha)-stimulated growth was completely inhibited by concentrations > or =0.3 microM in the PE01 and PE04 cell lines and by > or =0.1 microM in SKOV-3 cells. TGF-alpha inhibition of PE01CDDP growth was reversed by concentrations > or =0.1 microM ZM 252868. TGF-alpha-stimulated tyrosine phosphorylation of both the EGF receptor and c-erbB2 receptor in all four cell lines. The inhibitor ZM 252868, at concentrations > or =0.3 microM, completely inhibited TGF-alpha-stimulated tyrosine phosphorylation of the EGF receptor and reduced phosphorylation of the c-erbB2 protein. EGF-activated EGF receptor tyrosine kinase activity was completely inhibited by 3 microM ZM 252868 in PE01, SKOV-3 and PE01CDDP cells. These data indicate that the EGF receptor-targeted TK inhibitor ZM 252868 can inhibit growth of ovarian carcinoma cells in vitro consistent with inhibition of tyrosine phosphorylation at the EGF receptor.

Dynamics of reactive oxygen intermediate production in human glioma: n-6 essential fatty acid effects

BACKGROUND

Reactive oxygen intermediates (ROIs) are important signals controlling cell growth and cell death. Local essential fatty acid (EFA) deficiencies in tumour cells may limit tumour ROI generation. This deficiency may be rectified by the addition of exogenous EFA.

MATERIALS AND METHODS

The n-6 EFA effects on tumour ROIs were analysed in terms of kinetics, dose-response and individual cell type responses using flow cytometry of intracellular 2',7'-dichlorofluorescin oxidation. ROI formation in 30 gliomas and five paired samples of normal brain tissue, > 500 000 cells per specimen, was analysed every 10 s for 0-25 min.

RESULTS

Tumour cell basal ROI was lower than normal brain tissue ROI from the same subjects (P < 0.00002). Normal and tumour cell ROIs were stimulated by 4-40 micromol L-1 n-6 EFAs, arachidonic acid (AA) and gamma-linolenic acid (GLA). The stimulated ROI rate was exponential, with the maximum dependent on EFA concentration and tumour grade.

CONCLUSIONS

EFAs stimulated tumour cells more than normal cells (P < 0.0000017, n = 71) and increased ROIs in glial fibrillary acidic protein-positive cells in tumours. This indicated high sensitivity of glioma cell ROIs to n-6 EFAs.

Apoptosis in human primary brain tumours: actions of arachidonic acid

It has been postulated that loss of proliferative control in tumour cells is a consequence of depletion of cellular arachidonic acid (AA) and that exogenous AA and n-6 fatty acids may restore control of proliferation. To test this hypothesis and to investigate the activity of AA, apoptosis in human primary brain tumour cells was analysed using flow terminal deoxynucleotide transferase uridine nick end-labelling (TUNEL). The effect of exogenous AA (30 microM) was analysed in collagenase-dispersed tissue from seven human primary brain tumours and in the normal brain tissue surrounding one of the tumours. Exogenous AA stimulated apoptosis in tumour tissue. A rapid three-fold increase in endonuclease activity was detected in tumour cells incubated with AA. The increase in apoptosis was significantly greater than the contemporary (< 15%) increase in necrosis detected using propidium iodide permeability and was greater than AA effects on normal brain tissue. These results are consistent with activation of the pathways of apoptosis by AA.

Image registration: an essential part of radiation therapy treatment planning

PURPOSE

We believe that a three-dimensional (3D) registration of nonplanning (diagnostic) imaging data with the planning computed tomography (CT) offers a substantial improvement in tumor target identification for many radiation therapy patients. The purpose of this article is to review and discuss our experience to date.

METHODS AND MATERIALS

We reviewed the charts and treatment planning records of all patients that underwent 3D radiation treatment planning in our department from June 1994 to December 1995, to learn which patients had image registration performed and why it was thought they would benefit from this approach. We also measured how much error would have been introduced into the target definition if the nonplanning imaging data had not been available and only the planning CT had been used.

RESULTS

Between June 1994 and December 1995, 106 of 246 (43%) of patients undergoing 3D treatment planning had image registration. Four reasons for performing registration were identified. First, some tumor volumes have better definition on magnetic resonance imaging (MRI) than on CT. Second, a properly contrasted diagnostic CT sometimes can show the tumor target better than can the planning CT. Third, the diagnostic CT or MR may have been preoperative, with the postoperative planning CT no longer showing the tumor. Fourth, the patient may have undergone cytoreductive chemotherapy so that the postchemotherapy planning CT no longer showed the original tumor volume. In patients in whom the planning CT did not show the tumor volume well an analysis was done to determine how the treatment plan was changed with the addition of a better tumor-defining nonplanning CT or MR. We have found that the use of this additional imaging modality changed the tumor location in the treatment plan at least 1.5 cm for half of the patients, and up to 3.0 cm for 1/4 of the patients.

CONCLUSIONS

Multimodality and/or sequential imaging can substantially aid in better tumor definition in many patients undergoing 3D treatment planning. In some patients the appropriate nonplanning imaging source can change the perceived tumor location by several centimeters and is thus essential for proper treatment planning.

Transforming growth factor-beta isoform expression in human ovarian tumours

The expression patterns of members of the transforming growth factor-beta (TGF-beta) family were analysed in 96 primary ovarian tumours by RNAse protection assay. mRNA for the three mammalian isoforms, TGF-beta 1, TGF-beta 2 and TGF-beta 3, was detected in 46, 66 and 66% of 74 malignant tumours, respectively, with the predominant patterns of expression being either dual or triple co-expression. TGF-beta II receptor expression, detected by reverse-transcription PCR, was present in 92% malignant tumours. Expression patterns were similar between malignant, borderline and benign tumours, although TGF-beta 1 incidence was reduced in benign tumours. In malignant tumours, the incidence of TGF-beta 1 expression was less than that of either TGF-beta 2 (P = 0.02) or TGF-beta 3 (P = 0.0014), while in both malignant and borderline tumours, TGF-beta 2 and TGF-beta 3 tended to be co-expressed. Aneuploid tumours were more likely than diploid tumours to express multiple rather than single forms of TGF-beta (P = 0.018). The incidence of TGF-beta 1 expression was reduced in PR-moderate/rich (PR > 20 fmol/mg protein) relative to PR-negative/poor tumours (P = 0.048), while TGF-beta 3 expression was increased in ER-moderate/rich (ER > 20 fmol/mg protein) tumours compared to ER-negative/poor tumours (P = 0.0012). Expression of TGF-beta 3, but not TGF-beta 1 or TGF-beta 2, was associated with advanced stage disease (P = 0.014) and, in the malignant group, reduced survival (P = 0.02) with a hazard ratio of 2.6. These data suggest a possible role for TGF-beta 3 in the progression of ovarian cancer.

The expression of Ki-S1 and BCL-2 and the response to primary tamoxifen therapy in elderly patients with breast cancer

Ki-S1, a marker of proliferation, and bcl-2, the gene product of which is an antagonist of apoptosis, have been measured in 51 ER-positive primary breast cancers before and during tamoxifen treatment and then related to clinical response. Both markers were detected in the majority of tumours before treatment and, quantitatively, initial expression of Bcl-2 protein, but not Ki-S1, was significantly related to the percentage reduction in tumour volume as assessed by ultrasound. Staining for both markers was lower in post treatment samples than in those taken prior to treatments, but concordant decreases in staining indices were seen in only 11 of the 51 tumours. The results demonstrate, using clinical material, that the response to tamoxifen may involve changes in proliferation and/or susceptibility to cell-death.

Cell cycle effects of the novel topoisomerase I inhibitor NU/ICRF 505 in a panel of Chinese hamster ovary cell lines

The effect of the novel topoisomerase I inhibitor NU/ICRF 505 (20 microM, approximate IC50 concentration) on the cell cycle was studied by flow cytometry in four Chinese hamster ovary (CHO) cell lines. Postdrug treated cells were incubated with optimal concentrations of cytochalasin B to prevent re-entry of daughter cells into the cell cycle. NU/ICRF 505 had no significant effect on cell cycle distribution in the parent cell line (CHO-K1) and two mutants hypersensitive to topo II inhibitors (ADR-1, ADR-3), all of which express similar levels of topo I protein. In the drug-resistant variant ADR-r, which overexpresses topo I 2-fold, a significant accumulation of cells in G1 phase was recorded. These results are broadly consistent with the cell cycle effects expected in CHO cells by a classic topo I poison (camptothecin) and add weight to the view that NU/ICRF 505 induces cell death primarily through topo I inhibition.

c-erbB-3 protein expression in ovarian tumours

In this study the expression of c-erbB-3 protein was investigated in a range of human ovarian tumours using a monoclonal antibody (RTJ1) raised to a synthetic peptide from the cytoplasmic domain of the human c-erbB-3 protein. A total of 73 samples from 71 patients were graded as negative, weak, moderate or strong according to the intensity of immunohistochemical staining observed, and this was related to tumour characteristics and other clinical parameters. In terms of positivity vs negativity, of the 73 samples examined, 62 (85%) showed positive immunohistochemical staining for c-erbB-3. The majority of all ovarian tumours studied were positive for c-erbB-3 regardless of whether they were malignant (89%), borderline (100%) or benign (61%), however the incidence of positivity was significantly less in the benign group than in overtly malignant tumours (P = 0.03). c-erbB-3 positivity was not significantly associated with either age at diagnosis, tumour stage, differentiation, ploidy, percentage in S-phase or post-operative tumour bulk in malignant tumours. In terms of intensity of staining no significant difference was observed either within the common epithelial group or between this group and tumours of a benign nature. A significantly more intense pattern of c-erbB-3 staining was observed in tumours of borderline malignancy when compared with their overtly malignant counterparts (P = 0.002). Patients presenting with early-stage malignant tumours (I/II) were more likely to display intense tumour staining than those with late-stage disease (III/IV) (P = 0.04). These investigations suggest that c-erbB-3 protein is frequently expressed in both benign and malignant ovarian tumours, and that overexpression is more common in borderline and early invasive lesions.

The regulation of growth and protein expression by estrogen in vitro: a study of 8 human ovarian carcinoma cell lines

The effects of 17 beta-estradiol (E2) on the growth and the levels of estrogen receptor (ER), progesterone receptor (PR) and pS2 protein were examined in a range of 8 ovarian carcinoma cell lines. E2 stimulated growth of the 3 cell lines with an ER content of 80-220 fmol/mg protein but not the 5 cell lines with ER concentrations less than 20 fmol/mg protein. After exposure to E2, ER concentration in 2 of the 3 responsive cell lines was decreased relative to untreated cells and in 2 lines, progesterone receptors were increased. No change in steroid receptor levels was observed in cell lines with low or negligible levels of receptors. The pS2 protein was not induced by E2 in the 5 ovarian carcinoma cell lines examined. These results indicate that E2 can stimulate the growth of some ER-positive ovarian carcinoma cells and that these effects may be associated with changes in the cellular levels of steroid hormone receptors.

Growth control by epidermal growth factor and transforming growth factor-alpha in human lung squamous carcinoma cells

Although EGF receptor expression is generally elevated in human lung squamous carcinoma, the biological significance of this phenomenon and the role of EGF and TGF-alpha in this disease are poorly understood. We have investigated three human lung squamous carcinoma cell lines (NX002, CX140 and CX143) and have shown, using an antibody (EGFR1) directed against the EGF receptor, that the majority of cells in all three lines express the EGF receptor. Using a ligand binding assay, Scatchard analysis indicated high concentrations (1,300-2,700 fmol mg-1 protein) of a single low affinity binding site (Kd = 3-5 nM) within these lines. Addition of EGF or TGF-alpha at concentrations greater than 0.1 nM resulted in growth inhibition of all three lines and this was associated with an accumulation of cells in the G2/M phase of the cell cycle. Growth inhibitory effects were not explained by an enhancement of cellular differentiation as monitored by involucrin expression and the ability to form cornified envelopes. While the presence of EGF could not be detected in medium conditioned by the NX002 cell line, mRNA for TGF-alpha was detected in all three lines suggesting the possibility of an autocrine loop. These results together with reports of growth inhibition by EGF and TGF-alpha in other systems suggest that EGF and similar molecules might have a growth regulatory role in lung cancer cells and modulation of such may have therapeutic potential.

Mitogenic effects of epidermal growth factor and transforming growth factor-alpha on EGF-receptor positive human ovarian carcinoma cell lines

The role of epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) in the growth modulation of three human ovarian adenocarcinoma cell lines, PEO1, PEO4 and PEO14, has been examined by measuring responses of the cells growing in monolayer culture to exogenous addition of the growth factors. The presence of EGF receptors in the cell lines has been confirmed by ligand binding and immunocytochemical staining using a monoclonal antibody directed against the EGF receptor. The growth of all three cell lines was stimulated by both EGF and TGF-alpha. Dose-response effects were noted with the greatest growth stimulation occurring at concentrations between 0.1 and 10 nmol/l. The stimulatory effects of EGF and TGF-alpha were accompanied by changes in the cell cycle distribution as detected by flow cytometric analysis. It is concluded that EGF and TGF-alpha are important growth regulators in these EGF-receptor positive ovarian cancer cells.

Characterisation and properties of a small cell lung cancer cell line and xenograft WX322 with marked sensitivity to alpha-interferon

Controversy exists as to whether interferons usefully influence the growth of epithelial carcinomas. A small cell lung carcinoma (SCLC) cell line, WX322, has been derived which is greater than 1000-fold more sensitive to alpha-interferon (IFN) when grown in agar than other reported SCLC cell lines. The WX322 line has been characterised to prove its epithelial origin and its chemosensitivity compared with that of the NCI-H69 small cell line. The WX322 cell line expresses neuroendocrine and epithelial markers and possesses a morphology consistent with SCLC origin. A concentration of 5 IU ml-1 of IFN produced 50% inhibition of colony formation in agar in the WX322 line, whereas a concentration of greater than 10(5) IU ml-1 was required to produce a comparable effect with the NCI-H69 cell line. In contrast, WX322, possessed similar sensitivity to NCI-H69 cells when exposed to a range of cytotoxic agents. Analysis of the cell cycle indicated that IFN increased the percentage of cells in the G0/G1 phase for the WX322 cell line but increased the percentage in S phase for the NCI-H69 line. Growth of the xenograft, from which the cell line was derived, was also inhibited by IFN at doses greater than 10(5) IU/mouse/day. The WX322 cell line whether grown in agar or as a xenograft shows an unusually high sensitivity to IFN and provides an interesting model for studying mechanisms of IFN cytotoxicity to epithelial cells.

Surfactant replacement therapy. Innovative care for the premature infant

Prematurity is one of the most perplexing problems in perinatal care. Since the discovery of a surfactant deficiency as the primary etiology of hyaline membrane disease, attempts have been made to supplement surfactant in the premature infant. Surfactant replacement therapy is a promising new treatment for the premature infant with hyaline membrane disease. The history of surfactant replacement therapy, current trials of this therapy, nursing care of the infant receiving surfactant replacement, and future directions for nursing research in this area are discussed. Infants receiving this therapy require special nursing care to assure the best possible outcome. Nursing interventions at the time of delivery as well as those required in the neonatal intensive care unit are discussed.

Paraffin section immunophenotyping of non-Hodgkin's lymphoma, using a panel of monoclonal antibodies

The monoclonal antibodies F8-11-13, 4KB5, MB1, and MB2 recognize largely B-cell-restricted antigenic determinants that resist routine processing. Similarly, MT1, MT2, and UCHL1 react with fixation-resistant T-cell-restricted antigens. In order to evaluate the diagnostic potential of these antibodies, the authors have assessed their immunoreactivity with a series of 81 formalin-fixed and paraffin-embedded non-Hodgkin's lymphomas (48 B-cell, 33 T-cell) encompassing a wide variety of histologic subtypes, which had been fully characterized by frozen-section immunophenotyping. Ninety-six percent of B-cell lymphomas reacted with one or more of the B-cell-associated antibodies, whereas 100% of T-cell lymphomas reacted either with MT1, UCHL1, or both antibodies. MT2 was of no value in distinguishing between B- and T-cell lymphomas. None of the antibodies was entirely lineage specific; furthermore, a proportion of cases failed to react with one or more of the B- or T-cell-associated antibodies. Although these antibodies provide useful information in distinguishing between T- and B-cell lymphomas, the authors suggest that a panel of these antibodies is necessary for accurate determination of the histogenesis of these tumors. As with any immunohistochemical marker, interpretation of the immunostaining must be in the context of the morphologic features.