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Characterization of lymphoma-derived cell lines: comparison of cell lines positive and negative for Epstein-Barr virus nuclear antigen. II. Surface markers.

Fifteen of 16 lymphoma-derived cell lines and the Faji and P3HR1 cell lines were characterized with regard to certain surface markers, particularly immunoglobulins, complement receptors, Epstein-Barr virus (EBV) receptors, and Fc receptors. Ten lines positive for EBV nuclear antigen (EB-pos) were stained weakly or not at all by antihuman immunoglobulin fluorescein isothiocyanate conjugates, whereas EBV nuclear antigen negative (EB-neg) cell lines stained brightly. EB-pos lines frequently manifested Fc receptors, particularly for 7S antibody, whereas EB-neg lines did not. Receptors for the C3b component of complement and for EBV, which correlated significantly with each other, were expressed to a much lesser extent by EB-neg lines than by EB-pos lines. These findings are pertinent to an understanding of the infrequent association of this virus with American undifferentiated lymphomas of the Burkitt's and non-Burkitt's types.

Antigens, Viral↗

Characterization of a breast cancer cell line derived from a germ-line BRCA1 mutation carrier.

A tumor cell line, HCC1937, was established from a primary breast carcinoma from a 24-year-old patient with a germ-line BRCA1 mutation. A corresponding B-lymphoblastoid cell line was established from the patient's peripheral blood lymphocytes. BRCA1 analysis revealed that the tumor cell line is homozygous for the BRCA1 5382insC mutation, whereas the patient's lymphocyte DNA is heterozygous for the same mutation, as are at least two other family members' lymphocyte DNA. The tumor cell line is marked by multiple additional genetic changes including a high degree of aneuploidy, an acquired mutation of TP53 with wild-type allele loss, an acquired homozygous deletion of the PTEN gene, and loss of heterozygosity at multiple loci known to be involved in the pathogenesis of breast cancer. Comparison of the primary tumor with the cell line revealed the same BRCA1 mutation and an identical pattern of allele loss at multiple loci, indicating that the cell line had maintained many of the properties of the original tumor. This breast tumor-derived cell line may provide a useful model system for the study of familial breast cancer pathogenesis and for elucidating BRCA1 function and localization.

Adult↗

Secretion of gelatinases and tissue inhibitors of metalloproteinases by human lung cancer cell lines and revertant cell lines: not an invariant correlation with metastasis.

Numerous studies have reported a correlation between production of 72-kDa (MMP-2) and 92-kDa (MMP-9) type-IV collagenases/gelatinases and the metastatic potential of cancer cells. An abrogating effect of tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) on metastases has also been noted. In this report we have used sensitive enzyme-linked immunoassays to measure MMP-2, MMP-9, TIMP-1 and TIMP-2 levels in eight human lung-cancer cell lines which were characterized for biological behavior in nude mice. We demonstrated that the Calu-6 and A549 cell lines with the highest metastatic, invasive and tumorigenic potential secreted the highest levels of MMP-2. MMP-9 and TIMP-1 secretions were comparatively low in all cell lines. TIMP-2 secretion, which exceeded MMP-2 secretion for all cell lines, did not correlate with metastatic potential. To further explore these correlations, the metastatic Calu-6 cell line was transfected with a K-rev-1 cDNA expression construct. The K-rev revertant cell lines demonstrated a more differentiated phenotype and were less tumorigenic, invasive and metastatic in nude mice. Nonetheless, the Calu-6 revertant cell lines secreted higher levels of MMP-2 than the parent cell line. In conclusion, invasion and metastasis by lung-cancer cells requires not only enhanced MMP production, but also other less well-understood tumorigenic characteristics. The multiplicity of factors required by cancer cells for dissemination helps to explain the minute fraction of cancer cells from a primary tumor that ever develop into a metastasis.

Animals↗

Differential cyclic AMP responses to calcitonin among human ovarian carcinoma cell lines: a calcitonin-responsive line derived from a rare tumor type.

Several human tumor cell lines have been reported to have specific receptors for calcitonin (CT) and CT-responsive adenylate cyclase. In order to correlate patterns of responsiveness to CT, parathyroid hormone (PTH) and prostaglandin E2 (PGE2) with tumor morphology and intermediate filament protein expression, we examined four human ovarian tumor cell lines (BIN-16, BIN-22, BIN-53, BIN-67) which had been cultured from cells of metastatic foci. In two cell lines (BIN-53 and -16) there were small increases in cAMP content after exposure to CT and in three cell lines (BIN-53, -16, and -22) larger increases with PGE2. There was no cAMP response in any of the cells to PTH. In BIN-67 cells, however, CT induced a striking (greater than 20-fold) increase in cAMP content. Histologically, the CT-nonresponsive tumor lines were derived from serous adenocarcinomas while the CT-responsive tumor line was from a rare small cell carcinoma. Gel electrophoretic and immunofluorescence microscopic analyses had previously disclosed that the CT-nonresponsive cell lines contained high levels of simple epithelial keratins and no or very low levels of vimentin (characteristic of ovarian surface epithelial cells), while the CT-responsive cell line contained almost exclusively vimentin. Thus, cells cultured from a rare type of ovarian tumor were CT-responsive and were distinguishable from CT-nonresponsive ovarian tumor cells by initial tumor histology and intermediate filament protein expression.

Calcitonin↗

Determination of quinolones and fluoroquinolones in hospital sewage water by off-line and on-line solid-phase extraction procedures coupled to HPLC-UV.

In this work, the development of two solid-phase extraction procedures (off-line and on-line formats) for the identification and quantification of several (fluoro)quinolones in hospital sewage water by HPLC-UV is described. Both procedures are based on the use of C18 and anion exchange (SAX) sorbents for the preconcentration and clean-up steps, respectively, and all variables influencing both steps were optimised. In the off-line format, after its pH was adjusted to 2.5, sample was preconcentrated on a C18 cartridge and eluted with 4 mL of methanol/ammonia (94/6). The methanolic extract must be diluted up to 10 mL with water to allow quantitative retention of the analytes on the SAX cartridge. In the on-line format, the addition of 2.5% of NH4Cl to the sewage water sample (pH = 2.5) was necessary to increase the breakthrough volumes of the analytes in the C18 precolumn. Quantitative transfer of the (fluoro)quinolones from the C18 precolumn to the SAX precolumn was accomplished by pumping 2 mL of a mixture methanol/water (40/60, pH = 9.2) at 2 mL min(-1). Elution of the analytes from the SAX precolumn by means of the chromatographic mobile phase required the inclusion of an additional isocratic step at the beginning of the gradient program. Both off-line and on-line solid phase extraction procedures coupled to HPLC-UV were applied to the analysis of a sewage water sample collected in the sewer system at the output of the St Dimphna Hospital (Geel, Belgium). The fluoroquinolone ciprofloxacin was found in this sample and quantified at 5.8 +/- 0.4 microg L(-1) (off-line method) and 5.6 +/- 0.5 microg L(-1) (on-line method). The analysis of spiked samples containing the seven (fluoro)quinolones studied provided quantitative recoveries in all cases with low RSD values (from 6 to 12%), and all the analytes could be identified by means of their UV spectra with match factors varying from 950 to 985 depending on the (fluoro)quinolone.

Chromatography, High Pressure Liquid↗

A new model for "accept or reject" strategies in off-line and on-line megavoltage treatment evaluation.

PURPOSE: With megavoltage on-line imaging, a temporal record of the treatment setup variation is made available during the course of radiotherapy. This work describes the theoretical framework where the imaging data is incorporated as feedback for deriving off-line and on-line "accept or reject" decisions to improve the quality of radiotherapy on an individual patient basis. METHODS AND MATERIALS: A dynamic model of treatment setup variation is developed to describe: (a) the variations of multifraction treatment position and (b) the variation of measurement. Based on this model, a confidence region of subsequent treatment position is estimated from measurements of previous treatment position. The confidence region is compared with an allowance region of the treatment position, representing the acceptable margin of setup variation. The difference of the two regions are then evaluated to derive off-line and on-line "accept or reject" treatment decisions. RESULTS: The model was simulated retrospectively using sequential daily images from different treatment sites. "Accept or reject" decisions were produced for on-line and off-line applications. The results also demonstrate the ability of the model to include the effects of setup variation that drifted during the course of treatment. CONCLUSION: The preliminary result demonstrates that "accept or reject" treatment decisions can be derived quantitatively from on-line imaging data. The model shows potential to guide the physician and therapist in implementing efficient and accurate treatment adjustments. Further work is required to test the model in the clinical setting.

Humans↗

Molecular cloning of IGFBP-5 from SCLC cell lines and expression of IGFBP-4, IGFBP-5 and IGFBP-6 in lung cancer cell lines and primary tumours.

We showed recently that insulin-like growth factor binding protein (IGFBP)-1, -2 and -3 are differentially expressed in lung cancer and permanent lung cancer cell lines. Elevated levels of IGF binding capacity in serum of lung cancer patients were also reported. The function and tissue specificity of IGFBP are still obscure but they are probably local regulators of IGF action. Here we show the expression of IGFBP-4 transcripts in 11/11 small cell lung cancer (SCLC) cell lines, in nine out of 11 non-small cell lung cancer (NSCLC) cell lines, in 11/11 lung tumour specimens (10 derived from patients with NSCLC and one from SCLC origin) and in normal lung. In addition we isolated IGFBP-5 cDNA from lambda gt10 libraries of SCLC cell lines. With this IGFBP-5 cDNA we detected transcripts of different lengths in seven out of 11 SCLC cell lines, in 11/11 lung cancer specimens but only in one out of 11 NSCLC cell lines and in normal lung. IGFBP-6 was not detected in northern analysis of any tested SCLC cell line but it was expressed in nine out of 11 NSCLC cell lines and in nine out of 11 human lung cancer specimens and in normal lung.

Base Sequence↗

Changes in ocular torsion position produced by a single visual line rotating around the line of sight--visual "entrainment" of ocular torsion.

A large- or full-field visual stimulus slowly rotating around the naso-occipital axis of an observer causes both eyes to tort, and many of the factors controlling this optokinetic torsional response have been identified. The present study reports that a single line rotating about the line of sight can cause both eyes to tort in the same direction as the stimulus but with a low gain. We have used the term 'entrainment' to describe this torsional response. This paper reports some of the factors associated with entrainment. Video measures of 3-d eye position were recorded while the subject made settings of a simple visual line to subjective visual horizontal (SVH) and vertical (SVV) using the standard method-of-adjustment paradigm. The visual line was composed of 11 light-emitting diodes; the line subtended a visual angle of 19 degrees, and moved at a constant speed of 4.8 degrees /s. Settings were made in an otherwise darkened room, and also in the light. Subjects were required to maintain fixation of the central LED while making settings from starting positions 10 or 20 degrees either side of gravitational horizontal or vertical. We show that entrainment of ocular torsion by the single moving visual line is low in gain but a reliable and repeatable effect and that (1) there are considerable individual differences between subjects but within-subject consistency, (2) all subjects show larger and more consistent torsional entrainment for lines moving to SVH than lines moving to SVV, (3) the strongest entrainment generally occurs within about 10 degrees of the target position, and (4) entrainment is also present in the light, though with slightly reduced gain.

Adaptation, Ocular↗

Utility of a C57BL/6 ES line versus 129 ES lines for targeted mutations in mice.

Inbred ES lines, though useful for generating targeted mutations in mice, are used infrequently. To appreciate the relative efficiency of inbred ES lines, a C57BL/6 ES line was compared with 129 strain ES lines for effectiveness in chimera formation leading to the establishment of targeted mutations in mice. Data from a transgenic facility spanning 7 years were collected. C57BL/6 ES cells injected into Balb/c embryos results in lower coat color chimerism than do 129 ES cells injected into C57BL/6 embryos. Combined data indicate that five independent targeted C57BL/6 clones should be injected as compared to three independent 129 clones to generate enough chimeras to effectively test for germ-line transmission. Thus, although less efficient than 129 ES lines, the C57BL/6 ES line is a relatively competent line and useful for the routine generation of targeted mutations in mice on a defined genetic background.

Animals↗

Inheritance of breast muscle morphology in a line of turkeys selected for increased egg production, its randombred control line, and reciprocal crosses between them.

Breast muscle morphology was studied at 16 wk of age in a line (E) selected over 45 generations for increased egg production, its randombred control line (RBC1), and reciprocal crosses between the E and RBC1 lines. A sample of 10 birds per genetic group-sex subgroup was killed with restraint to prevent flapping of the wings. The skin was removed from the breast region and a sample of breast muscle was obtained in a manner to prevent contraction. The muscle samples were dehydrated, cleared, embedded in paraffin, sectioned, incubated, and rehydrated before staining with hematoxylin and eosin. Four sections from the same muscle from each bird were placed on a slide and the slides were viewed for muscle morphology characteristics with a microscope and digitally recorded. Five fields of each section were viewed. Representative sections of each bird were given a score by 4 individuals based on breast muscle morphology. The scores ranged from 1 (little extracellular matrix and indistinct muscle fibers) to 5 (large extracellular space and distinct muscle fibers). Scores from 2 to 4 were intermediate to these extremes. The data were analyzed for sexes separate and combined. The E line had lower breast muscle morphology scores than the RBC1 line for males and sexes combined, indicating additive genetic variation in the scores. Nonadditive genetic variation was not an important source of variation for breast muscle morphology scores based on the contrast of the average of the parental lines with the average of the reciprocal crosses for males, females, or sexes combined. In 5 of 6 possible comparisons, the breast muscle morphology scores of the reciprocal cross were not significantly different from the line of the dam in the reciprocal cross. The only exception was for the E sire x RBC1 dam cross based on the data for females, wherein the breast muscle morphology scores were higher in the cross than in the pure RBC1 line. The results of the current study confirm the maternal inheritance of breast muscle morphology scores at 16 wk of age that has been previously reported.

Animals↗

Proper arrangement of the lines and cables in the setup of the laparoscopic surgery: development of new device "Line-Hanger".

Recently, with the rapid progress and introduction of new machineries and instruments for endoscopic surgery, the connecting lines and cables connecting machineries around the operating field are becoming more and more complicated. The lines and cables are often very troublesome, especially when the operator and assistant change their positions, and sometimes they are not only annoying but also potentially dangerous during the operative procedure. We feel there is a pressing need to develop a device to regulate the lines and cables. We developed a device for regulating the lines and cables in cooperation with Olympus Optical Co, Ltd (Tokyo, Japan) and named it "Line-Hanger." We have used it in more than 30 cases of various kinds of endoscopic surgery. In this study, we compare the usefulness of the "Line-Hanger" with the conventional method: fixation of lines and cables to the drapes with Velcro(R). The girth of the operative personnel are freed from a jumble of cables, and they become ergonomically comfortable. Especially when operator and assistant are changing their position, it becomes very smooth. "Line-Hanger" is extremely useful for endoscopic surgery.

Humans↗

Characterization of a newly established human acinic cell adenocarcinoma cell line (HACC) originating from the salivary gland: morphological features and role of various growth factors on the growth of the HACC cell line.

Human acinic cell adenocarcinoma cell (HACC) line was established from the pleural effusion that contains metastatic tumor cells of acinic cell adenocarcinoma of papillary and microcystic type originating from the parotid gland. The HACC cells grew in an adherent monolayer with a doubling time of 66 h. Implanted tumor of SCID mice revealed similar histological findings to that of the primary tumor. The HACC cells produced mucin and expressed epithelial markers as well as alpha1-antitrypsin and lysozyme, whereas salivary peptide P-C was expressed in cultured HACC cells but not in the primary and implanted HACC cell tumors. S-100 protein was also expressed in both the primary tumor and HACC cell line. Neither amplification of common oncogenes nor expression of p53 was observed. The receptor for epidermal growth factor (EGF) was expressed, indicating EGF and transforming growth factor-alpha (TGF-alpha) enhanced the growth of the HACC line. Unexpectedly, tumor necrosis factor-a (TNF-alpha) also enhanced the growth of the HACC line significantly. However, there was no evidence of autocrine growth using these growth factors. In contrast, TGF-beta1 inhibited the growth of the HACC cell line through apoptosis. The HACC cell line has features similar to both acinar and intercalated ductal cells of the salivary gland. Epidermal growth factor, TGF-alpha and TNF-alpha are potential growth factors for the HACC cell line. The HACC cell line may be a good model for studying the biological behavior of salivary gland neoplasms.

Animals↗

Characterization of Fc epsilonRI expressing human monocytic cell lines. 1. The role of CD45 on signal transduction in primary monocytes and cell lines.

BACKGROUND: Recently, the high affinity receptor for IgE (Fc epsilonRI), which plays a major role in allergies, has been identified on a number of different antigen-presenting cell types, including human monocytes from atopic and nonatopic donors. In this report human monocytic cell lines were used to test for the expression of Fc epsilonRI, reasoning that a monocytic cell line expressing Fc epsilonRI constitutively would be a useful tool for large scale studies on the regulation of IgE binding and signal transduction. METHODS: Reverse transduction polymerase chain reaction was applied to identify Fc epsilonRI alpha-chain message, flow cytometry to detect Fc epsilonRI surface expression and signal transduction on the cell lines generated by transfection. RESULTS: We report the establishment of monocytic cell lines constitutively expressing Fc epsilonRI (THP1-alpha01 to THP1-alpha40) generated by transfection of the cell line THP1 with a plasmid encoding the Fc epsilonRI alpha-chain only. Fc epsilonRI on the THP1-alpha lines specifically binds IgE and is functional with regard to ligand binding and signal transduction. Comparative studies between the transfectants and primary human monocytes from nonatopic donors demonstrated the regulatory role of the tyrosine phosphatase CD45 on Fc epsilonRI-mediated cell activation. CONCLUSIONS: Monocytic cell lines carry Fc epsilonRI alpha-chain RNA and enhancement by transfection results in surface Fc epsilonRI expression on THP1. Triggering the receptor on the THP1-alpha lines or on human monocytes, which express native Fc epsilonRI, elicits a rapid and transient calcium mobilization, prevented by co-cross-linking of Fc epsilonRI and CD45.

Calcium↗

Intravenous vinorelbine as first-line and second-line therapy in advanced breast cancer.

PURPOSE: We evaluated single-agent intravenous (IV) vinorelbine as first- and second-line treatment for advanced breast cancer (ABC) in patients who were not resistant to anthracyclines. Objective tumor response (TR) and toxicity were assessed. PATIENTS AND METHODS: A total of 107 women were enrolled onto this multicenter, nonrandomized, open-label phase II study. Patients were stratified into first- and second-line treatment groups, based on prior treatment history. Vinorelbine was initially given at 30 mg/m2/wk, with dose modification for toxicity as indicated. Therapy was continued until disease progression or severe toxicity mandated withdrawal or until the patient asked to be removed from the study. RESULTS: The objective response rate for all patients was 34% (95% confidence interval [CI], 25% to 44%): 35% (95% CI, 23% to 48%) for first-line patients and 32% (95% CI, 20% to 47%) for second-line patients. Nine first-line and three second-line patients obtained a complete response (CR). The median duration of objective response was 34 weeks in both groups. The overall survival durations of first- and second-line patients were 67 weeks and 62 weeks, respectively. Granulocytopenia was the predominant dose-limiting toxicity. Two patients died on study as a result of granulocytopenic sepsis. CONCLUSION: Single-agent vinorelbine is an effective and well-tolerated agent for first- and second-line therapy of ABC. The results of this study confirm the findings of similar international trials and suggest vinorelbine should be considered a valid treatment option for patients with ABC and a potential component in future combination regimens for this disease.

Adult↗

CT analysis of defects of the cement mantle and alignment of the stem: in vitro comparison of Charnley-Kerboul femoral hip implants inserted line-to-line and undersized in paired femora.

Using a modern cementing technique, we implanted 22 stereolithographic polymeric replicas of the Charnley-Kerboul stem in 11 pairs of human cadaver femora. On one side, the replicas were cemented line-to-line with the largest broach. On the other, one-size undersized replicas were used (radial difference, 0.89 mm sd 0.13).CT analysis showed that the line-to-line stems without distal centralisers were at least as well aligned and centered as undersized stems with a centraliser, but were surrounded by less cement and presented more areas of thin (< 2 mm) or deficient (< 1 mm) cement. These areas were located predominantly at the corners and in the middle and distal thirds of the stem. Nevertheless, in line-to-line stems, penetration of cement into cancellous bone resulted in a mean thickness of cement of 3.1 mm (sd 0.6) and only 6.2% of deficient and 26.4% of thin cement. In over 90% of these areas, the cement was directly supported by cortical bone or cortical bone with less than 1 mm of cancellous bone interposed. When Charnley-Kerboul stems are cemented line-to-line, good clinical results are observed because cement-deficient areas are limited and are frequently supported by cortical bone.

Arthroplasty, Replacement, Hip↗

[What is the objective of second-line chemotherapy after failure of first-line chemotherapy in hormone-resistant metastatic prostate?].

UNLABELLED: Chemotherapy occupies an increasingly important place in the management of hormone-resistant metastatic prostate cancer. For the first time in this disease, docetaxel increases the survival of patients, with a modest, but definite median gain of about 2 months. In everyday practice, the indication for second-line chemotherapy after immediate or delayed failure of first-line chemotherapy is sometimes considered, although objective data concerning its efficacy are limited. The objective of the present study was to retrospectively evaluate the results obtained with second-line chemotherapy in a patient cohort managed at the Montpellier Regional Cancer Centre. PATIENTS AND METHODS: Clinical characteristics, treatments delivered and outcome of 43 patients who received two successive lines of chemotherapy were retrospectively collected by means of a standardized questionnaire. Three groups of patients were defined as a function of the chemotherapy protocols delivered: docetaxel alone or in combination, mitoxantrone and other protocols not comprising either docetaxel or mitoxantrone. Responses to chemotherapy were analysed according to three criteria: objective responses, laboratory responses and palliative responses. RESULTS: At the time of second-line chemotherapy, the median age of the patients was 69 years (range: 46 to 83). The median interval between the end of first-line chemotherapy and the start of second-line chemotherapy was 3 months (range: 1 to 15). The protocols administered comprised docetaxel alone (12 patients) or in combination with cisplatin (4 patients), mitoxantrone in 13 patients, or other cytotoxic molecules such as vinblastine, doxorubicin or etoposide in combination with a platinum salt (14 patients). The median number of cycles delivered was 4 (range: 1 to 10). No objective response was observed. Six (14%) patients obtained a laboratory response. A palliative response was observed in 16 (37%) patients, 7 of whom were treated with a docetaxel-based protocol, 6 were treated with mitoxantrone and 3 were treated by other protocols. The median duration of palliative response was 3 months (range: 1 to 6). The median survival was 8 months (range: 1 to 24), with no significant difference between the various protocols. CONCLUSION: In 2006, the objective of second-line chemotherapy in patients with hormone-resistant prostate cancer appears to be purely palliative. No reference protocol has been defined among currently available cytotoxic molecules. The indication must therefore take into account the benefit/risk balance to avoid compromising the patients quality of life. Therapeutic trials are essential to develop effective new molecules.

Aged↗

Membrane characteristics of established human T- and B-cell lines. Cross-reactivity of human T-antigenic determinants with peripheral lymphocytes of non-human primates and the presence of MLC antigens on cultured T-cell lines.

Human T-cell lines (MOLT-4 and SOMMER-T) were injected into rabbits and monkeys (stumptail and squirrel monkeys). Rabbit anti-MOLT serum was absorbed with human liver and cultured B cells. Absorbed anti-MOLT serum was cytotoxic to lymphocytes of baboons and stumptail monkeys. Rabbit anti-MOLT and SOMMER-T sera after absorption with liver and B cell showed florescent ring formation in baboon and stumptail lymphocytes by using immunoflurescence techniques. On the other hand, antisera against MOLT and SOMMER-T cells in stumptail and squirrel monkeys were not only cytotoxic to MOLT and SOMMER-T cells, but also to other T-cell lines, CCRF-CEM and CCRF-HSB-2 cells. Cultured B-cell lines stimulated allogeneic and xenogeneic (rabbit and monkeys) lymphocytes far better than cultured T-cells lines did. T-cell lines, CCRF-HSB-2 and SOMMER-T (number 8402), gave small but significant stimulation to allogenic lymphocytes especially in the presence of foetal calf serum. MOLT-4B failed to stimulatie allogeneic lymphocytes. When lymphocytes of non-human primates and rabbit were cultured with human B- and T-cell lines in the presence of foetal calf serum, CCRF-HSB-2 and SOMMER-T cells stimulated xenogeneic lymphocytes of rabbit, squirrel monkey and stumptail monkey. MOLT-4 cells stimulated lymphocytes of baboon to some extent. These results indicate that although cultured B-cell lines had more mixed lyphocyte reaction (MLR) stimulating structure than T-cell lines, the latter still maintained some stimulating structure on the membrances.

Animals↗

Functional hyaluronan receptors are expressed on a squamous cell lung carcinoma cell line but not on other lung carcinoma cell lines.

We investigated the production of hyaluronan and the presence of hyaluronan receptors in a panel of human lung carcinoma cell lines, consisting of small cell carcinomas (SCLC) and non-small cell carcinomas (non-SCLC). These transformed cell lines produced only minute amounts of hyaluronan, whereas normal lung fibroblasts synthesized high amounts. CD44 molecules (an integral membrane glycoprotein suggested previously to function as a hyaluronan receptor) were differentially expressed on non-SCLC cell lines but essentially not on the SCLC cell lines. In contrast, RHAMM molecules (receptor for hyaluronan-mediated motility) were preferentially expressed on SCLC cells. Although all the lung tumor cell lines expressed various amounts of CD44 and RHAMM, only the SCLC line U-1752 could bind [3H]hyaluronan. The binding sites were saturated with about 19,700 hyaluronan molecules (Mr 1.4 x 10(6)) bound per cell with a Kd of 0.16 x 10(-9) M. CD44 molecules were responsible for the binding activity since Hermes-1 antibodies that block the binding of hyaluronan to CD44 blocked the binding of [3H]hyaluronan to U-1752 cells. 4-Phorbol 12-myristate 13-acetate (PMA) treatment of U-1752 cells both increased the hyaluronan-binding activity in U-1752 cells as well as induced abrogation of cell-cell and cell-matrix interactions. Addition of hyaluronan inhibited the PMA-induced disassembly of the cells. The fact that CD44 molecules are able to bind [3H]hyaluronan only on the SCLC line U-1752 but not on other lung carcinoma cell lines may be of value as a marker for squamous cell carcinoma differentiation. Furthermore, the inhibitory effect of hyaluronan on the PMA-promoted cell disassembly suggest that hyaluronan surrounding squamous cell carcinoma cells may affect their migration and invasiveness.

Carcinoma, Non-Small-Cell Lung↗