Selective adhesion of functional microtubules to patterned silane surfaces

We show that microtubule polymers can be immobilized selectively on lithographically patterned silane surfaces while retaining their native properties. Silane films were chemisorbed on polished silicon wafers or glass coverslips and patterned using a deep UV lithographic process developed at the Naval Research Laboratory. Hydrocarbon and fluorocarbon alkyl silanes, as well as amino and thiol terminal alkyl silanes, were investigated as substrates for microtubule adhesion with retention of biological activity. Microtubules were found to adhere strongly to amine terminal silanes while retaining the ability to act as substrates for the molecular motor protein kinesin. Aminosilane patterns with linewidths varying from 1 to 50 microns were produced lithographically and used to produce patterns of selectively adhered microtubules. Microtubules were partially aligned on the patterned lines by performing the immobilization in a fluid flow field. Patterns were imaged with atomic force microscopy and differential interference contrast microscopy. Motility assays were carried out using kinesin-coated beads and observed with differential interference contrast microscopy. Kinesin bead movement on the patterned microtubules was comparable to movement on microtubule control surfaces.

Insulin-like growth factor-I is an autocrine regulator for the brain metastatic variant of a human non-small cell lung cell line

Insulin-like growth factor (IGF-I) is associated with autocrine and paracrine stimulation for cell growth and development of brain tumor cells. The function of IGF-I in the brain metastatic variant of human lung cancer cells is investigated. The cells used here were derived in vivo with intracarotid injection of human non-small cell lung carcinoma NCI-H226. The tumor was developed as a cultured cell line, H226Br. Unlike the parental cells, H226Br was tumorigenic in nu/nu nude mice. Reverse transcriptase-polymerase chain reaction showed that IGF-I transcript of H226Br is increased compared to that of parental cells. The amount of IGF-I secreted in cultured medium of H226Br is higher than that of cultured parental cells. The IGF-I receptor-specific antibody, alpha IR3, inhibits H226Br growth in serum-free culture. The results established that IGF-I is an autocrine growth regulator for human non-small cell lung cancer cells that progressed to brain.

Retinoic Acid Modulates Epidermal Growth Factor Receptor Expression in Human Lung Epithelial Cancer Cells

In human lung epithelial cancer cell line H460, an accumulation of epidermal growth factor receptors (EGF-R) was observed following treatment with 1 &mgr;M retinoic acid. An increae in (125)I-labeled EGF binding capacity was detected, which reached its highest level after 48 h of incubation with retinoic acid. Transiently increased autophosphorylation of EGF-R after 48 h of retinoic acid treatment correlated with enhancement of EGF binding capacity on the H460 cell surface. Nuclear run-on analysis indicated that retinoic acid upregulates transcription of the EGF-R gene, reaching a maximum at 48 h and decreasing after 72 h of treatment. When retinoic acid-treated cells were chased in drug-free medium, the increased EGF-R transcript level remained unchanged. Up-regulated expression of EGF-R in H460 cells is reflected by their increasing tumorigenicity phenotype. The results demonstrate that retinoic acid induces EGF-R synthesis in human lung cancer cells. Copyright 1995 S. Karger AG, Basel

Posttranscriptional regulation of epidermal growth-factor receptor expression by retinoic Acid in a human lung epithelial-cell line

Retinoic acid transiently induced expression of high levels of epidermal growth factor receptor (EGFR) in the human non-small cell lung carcinoma cell line H460a. Scatchard analysis revealed a 40-fold increase in the expression of EGFR on the cell surface of H460a cells within 48 h of treatment with 5 mu M concentrations of retinoic acid. RNase protection and nuclear run-off assays established that increases in EGFR expression in retinoic acid-treated cells were not the result of increased promoter activity of EGFR gene, but were more likely the result of a posttranscriptional mechanism. Immune complex kinase assays demonstrated that the EGFR induced by retinoic acid was functionally active. We conclude that retinoic acid exerts its control over expression of the EGFR in H460a cells through a posttranscriptional mechanism. Moreover, elevated EGFR might play a role in the increased tumorigenic potential exhibited by retinoic acid-treated H460a cells.

Differential down-regulation of epidermal growth factor receptors expressed in the metastatic variants of human lung cancer adenocarcinoma cell line DMS4C

The metastatic variants of human lung adenocarcinoma cell line DMS4C were established by selection in vivo. Lung, brain, spleen and liver metastatic tumors derived from intracarotid inoculation of athymic BALB/c mice were collected, and their corresponding variant cell lines established. The epidermal growth factor (EGF) receptor expression of the parental cell line as well as the metastatic variant cell lines were investigated. 125I-labeled EGF binding assays showed that there were two types of EGF receptors in both parental and metastatic variants. Compared to DMS4C, the EGF binding capacities were found to be down-regulated by 70, 79, 85 and 89% for lung, spleen, liver and brain variant, respectively. The dissociation constants of spleen, liver and brain EGF receptors were distinct from that of the parental cell line. The EGF receptor autophosphorylation activity of lung variant was shown to be down-regulated as shown by immune complex kinase assay that corresponded to EGF receptor numbers whereas kinase activities of the liver, spleen and brain variants EGF receptors were completely abolished. However, the 170 kilodalton EGF receptor was shown to be unaltered during metastasis. The results indicated that, during metastasis progression, the proliferation of adenocarcinoma cells may have adopted a different growth regulation that is independent of EGF receptor kinase-modulated autocrine pathway. The result also implies that other oncogene may emerge as the major growth regulator for distant metastasis of adenocarcinoma cancer cells. This work provides a model for understanding tumor metastasis progression of human lung cancer.

Percutaneous transcatheter treatment of an intracavitary aspergilloma

We describe a case of massive hemoptysis, secondary to an intracavitary aspergilloma, successfully treated by computed tomography (CT)-guided placement of a Cope-loop catheter with daily transcatheter instillation of amphotericin B and cavitary irrigation. Over a 15-day period, this regimen resulted in cessation of hemoptysis and radiographic resolution of the aspergilloma. No complications were encountered. A follow-up CT of the thorax showed no recurrence of the aspergilloma at 3 months.

Determination of plicamycin in plasma by radioimmunoassay

This article describes a method for the determination of plicamycin in plasma by radioimmunoassay. The anti-plicamycin antibody was produced against a plicamycin-bovine serum albumin conjugate prepared by using diazotized p-aminobenzoic acid as a cross-linker. The radiolabeled ligand, 125I-plicamycin, was prepared by the chloramine-T method. The linear plicamycin concentration range was 7-400 ng/ml. The coefficients of variation for intra- and interday variabilities were 7.5 and 15%, respectively. No interference was observed from either the structurally related chromomycin A or concomitantly used drugs hydroxyurea or allopurinol. With this method of testing, plicamycin levels in plasma could be determined in patients receiving small (0.85-1.0 mg/m2) therapeutic plicamycin doses. Preliminary pharmacokinetic data in humans indicate that the plasma drug disappearance curve was biphasic with a mean elimination half-life of 10.6 +/- 1.7 h, total clearance rate of 11.1 +/- 0.4 ml/min/m2, and area under the plasma drug concentration-time curve of 1,289-1,546 ng-h/ml. This assay method is clinically useful for pharmacokinetic studies of plicamycin and may be helpful in the design of rational therapeutic drug trials.

Autocrine growth stimulation by transforming growth factor-alpha in human non-small cell lung cancer

We studied the biological response to and production of transforming growth factor-alpha (TGF-alpha) by the non-small cell lung carcinoma (NSCLC) clonal cell lines H226b, H322a, H460a, H596b. Each of these cell lines expressed epidermal growth factor receptor (EGFR) as determined by [125I]EGF competitive binding and Scatchard analysis and by phosphorylation. The receptors were functionally active as determined in immune complex kinase assays. H322a, H226b, H460a, and H596b cells showed stimulated [3H]thymidine (Thd) uptake in response to TGF-alpha. Exogenously added TGF-alpha increased colony formation in soft agar for three of the cell lines in media containing serum. All cell lines expressed TGF-alpha detected by immunohistochemistry and TGF-alpha mRNA, although to differing degrees. Cell lysates and spent media competed for EGFR binding with EGF, thus demonstrating production of TGF-alpha-like activity. The anti-TGF-alpha monoclonal antibody AB-3 inhibited the uptake of [3H]Thd by proliferating H322a and H226b cells but not H460a and H596b cells. No inhibition occurred with MOPC21 antibody and inhibition was completely reversed by addition of TGF-alpha to the culture. Suramin inhibited cell proliferation and [3H]Thd uptake by all cell lines. Inhibition of H460a and H596b cells was reversed with exogenous TGF-alpha but not PDGF. Our data suggests that TGF-alpha is a mediator of autocrine growth stimulation for NSCLC cells, and that for some NSCLC cells cytoplasmic binding of receptor and ligand is the primary mechanism for autocrine growth stimulation.

Differential expression of the c-erbB-2 gene in human small cell and non-small cell lung cancer

We studied non-small cell lung cancers (NSCLC) from 60 patients for abnormalities in the c-erbB-2 gene. Eleven human lung cancer cell lines, including four derived from small cell lung cancer (SCLC) and seven derived from NSCLC were also examined for altered c-erbB-2 gene expression. Southern blot analysis of paired tumor and normal lung samples demonstrated that amplification of the c-erbB-2 gene is rare in NSCLC (2/60) and not restricted to adenocarcinomas. One patient showed an EcoRI restriction fragment length polymorphism for the c-erbB-2 locus. Four of four SCLC cell lines demonstrated minimal or nondetectable expression of c-erbB-2 mRNA compared to high levels of expression by seven of seven NSCLC lines. The highest expression levels were seen in four of four adenocarcinomas. We conclude that c-erbB-2 expression is different in SCLC compared to NSCLC and high expression of c-erbB-2 is consistently present in lung adenocarcinomas.

Skin graft from a scalp flap

We present a case of scalp avulsion treated with a transposition scalp flap utilizing a split-thickness skin graft from the flap. Using the flap as a donor site confined the operation to a single anatomic region and saved the patient an additional donor-site scar. The flap healed uneventfully with normal regrowth of hair, the donor site was well concealed, and there was complete take of the split-thickness skin graft.