CT imaging correlates of genomic expression for oral cavity squamous cell carcinoma.

BACKGROUND AND PURPOSE: Imaging correlates of genetic expression have been found for prognostic and predictive biomarkers of some malignant diseases, including breast and brain tumors. This study tests the hypothesis that imaging findings correlate with relevant genomic biomarkers in oral cavity squamous cell carcinoma. MATERIALS AND METHODS: Surplus frozen tissue from 27 untreated patients with oral cavity squamous cell carcinoma who underwent preoperative CT imaging was analyzed for gene expression. A team of neuroradiologists blinded to the genomic analysis results reviewed an extensive list of CT findings. The imaging correlated with genomic expression for cyclin D1, angiogenesis-related genes (vascular endothelial growth factor receptors and ligands), which relate to enhancement on the basis of other tumor types; and epidermal growth factor receptor, which may relate to proliferation and mass effect. RESULTS: Expression of vascular endothelial growth factor receptors 1 and 2 correlated with the enhancement of the primary tumor (P = .018 and P = .025, respectively), whereas the epidermal growth factor receptor correlated with mass effect (P = .03). Other exploratory correlations included epidermal growth factor receptor to perineural invasion (P = .05), and certain vascular endothelial growth factor receptors and ligands to mass effect (P = .03) and increased (P = .01) or decreased (P = .02) primary tumor size. CONCLUSIONS: We report that CT imaging correlates with gene expression in untreated oral cavity squamous cell carcinoma. Enhancement of the primary tumor and degree of mass effect correlate with relevant genomic biomarkers, which are also potential drug targets. Eventually, treatment decisions may be aided by combining imaging findings into meaningful phenotypes that relate directly to genomic biomarkers.

Augmenting understanding of the relationship between situation awareness and confidence using calibration analysis.

The present study represents a preliminary examination of the relationship between situation awareness (SA) and confidence within a distributed information-sharing environment using the calibration methodology. The calibration methodology uses the indices of calibration, resolution and over/under-confidence to examine the relationship between the accuracy of the responses and the degree of confidence that one has in these responses, which leads to a measure of an operator's meta-SA. The results of this study revealed that, although the participants were slightly overconfident in their responses, overall they demonstrated good meta-SA. That is, the participants' subjective probability judgements corresponded to their pattern of SA response accuracy. It is concluded that the use of calibration analysis represents a better methodology for expanding our understanding of the relationship between SA and confidence and ultimately how this relationship can impact decision-making and performance in applied settings than can be achieved by examining SA measures alone.

Effects of sleep loss on team decision making: motivational loss or motivational gain?

OBJECTIVE: To examine the effects of 30 hr of sleep loss and continuous cognitive work on performance in a distributed team decision-making environment. BACKGROUND: To date, only a few studies have examined the effect of sleep loss on distributed team performance, and only one other to our knowledge has examined the relationship between sleep loss and social-motivational aspects of teams (Hoeksema-van Orden, Gaillard, & Buunk, 1998). METHOD: Sixteen teams participated; each comprised 4 members. Three team members made threat assessments on a military surveillance task and then forwarded their judgments electronically to a team leader, who made a final assessment on behalf of the team. RESULTS: Sleep loss had an antagonistic effect on team decision-making accuracy and decision time. However, the performance loss associated with fatigue attributable to sleep loss was mediated by being part of a team, as compared with performing the same task individually - that is, we found evidence of a "motivational gain" effect in these sleepy teams. We compare these results with those of Hoeksema-van Orden et al. (1998), who found clear evidence of a "social loafing" effect in sleepy teams. CONCLUSION: The divergent results are discussed in the context of the collective effort model (Karau & Williams, 1993) and are attributable in part to a difference between independent and interdependent team tasks. APPLICATION: The issues and findings have implications for a wide range of distributed, collaborative work environments, such as military network-enabled operations.

Human LBP-32/MGR is a repressor of the P450scc in human choriocarcinoma cell line JEG-3.

Steroid hormones regulate a wide range of physiologic functions in humans. The cholesterol side-chain cleavage enzyme P450scc regulates the initial step of biosynthesis of all steroid hormones. We investigated the expression of P450scc by studying a potential regulator of P450scc, LBP-32/MGR. Using a Northern blot, we found that LBP-32/MGR mRNA was expressed mainly in the human placenta. Using radiation hybrid mapping, we identified LBP-32/MGR on human chromosome 2p25. Recombinant LBP-32/MGR protein bound preferentially to a DNA fragment from the promoter of P450scc in vitro and exhibited clear nuclear localization in transfected cells. Luciferase reporter gene assays showed that LBP-32/MGR specifically repressed transcriptional activation of the human P450scc promoter. Because placental P450scc expression is essential for pregnancy and steroid biosynthesis, the placental expression and transcriptional repressor activity of LBP-32/MGR in JEG-3 cells suggest it has a role as a transcriptional modulator of steroid biosynthesis.

Chemokines in cancer.

Chemokines are small, chemotactic cytokines that direct migration of leukocytes, activate inflammatory responses and participate in many other pleiotropic functions, including regulation of tumour growth. Chemokines modulate tumour behaviour by three important mechanisms: regulation of tumour-associated angiogenesis, activation of a host tumour-specific immunological response, and direct stimulation of tumour cell proliferation in an autocrine fashion. All of these mechanisms are promising points of cancer intervention, and preclinical mouse models suggest that chemokine antagonists and agonists could become important in the development of new anticancer therapies.

Characterization of human copine III as a phosphoprotein with associated kinase activity.

The copines, first described by Creutz et al. [(1998) J. Biol. Chem. 273, 1393-1402], comprise a two C2 domain-containing protein family and are known to aggregate phosphatidylserine membranes in a calcium-dependent manner. No enzymatic function has been attributed to copines yet. Due to a cross-reacting activity of Mikbeta1, an antibody to the IL-2Rbeta chain, we were able to serendipitously purify, partially microsequence, and clone human copine III. The 5 kb copine III transcript is expressed ubiquitously as determined by a multitissue Northern blot analysis. Phosphoamino acid analysis revealed phosphorylation of copine III on serine and threonine residues. In vitro kinase assays were performed with immunoprecipitated endogenous copine III, chromatography-purified endogenous copine III, and recombinant copine III expressed in Saccharomyces cerevisiae. The exogenous substrate myelin basic protein was phosphorylated in all in vitro kinase assays containing copine III immunoprecipitate or purified copine III. A 60-kDa band was observed in corresponding in gel kinase assays with staurosporine-activated cells. Cell lines expressing high levels of copine III protein had correspondingly high kinase activity in copine III antiserum immunoprecipitate. However, the copine amino acid sequences lack the traditional kinase catalytic domain. Therefore, the data suggest copine III may possess an intrinsic kinase activity and represent a novel unconventional kinase family.

Genomic cloning, mapping, structure and promoter analysis of HEADPIN, a serpin which is down-regulated in head and neck cancer cells.

Headpin is a novel serine proteinase inhibitor (serpin) that is down-regulated in squamous cell carcinoma of the oral cavity and in squamous cell carcinoma cell lines of the head and neck. Using a panel of 18q21.3 YAC clones, we mapped and cloned the HEADPIN gene. The gene spans 10 kb and is composed of eight exons and seven introns. The genomic structure is identical with some other ovalbumin serpins (ov-serpins) in terms of the numbers, position and phasing of the intron/exon boundaries. HEADPIN was mapped within the serpin cluster in 18q21.3 between MASPIN and SCCA2 as follows: cen-MASPIN-HEADPIN-SCCA2-SCCA1-tel. The transcription start site was determined and the promoter activity of the 5'-flanking region was analyzed. Luciferase promoter assays in HaCaT cells showed that the -432 to -144 nucleotide region has functional promoter activity. The activity of the promoter/enhancer was not observed in head and neck cancer cell lines TU167 and UMSCC1 which lack headpin expression. These data suggest that the differential expression of headpin in normal and carcinoma-derived cells is regulated at the transcriptional level. Understanding the genomic organization and transcriptional regulation of the ov-serpins clustered within 18q21. 3 provides a critical framework for assessing their potential role in cancer.

In vivo expression of the novel CXC chemokine BRAK in normal and cancerous human tissue.

Using differential display, we cloned a gene with reduced expression in short-term explants of head and neck squamous cell carcinoma (HNSCC) tumors compared to cultured normal oral epithelial cells. The differentially expressed gene was identical to the recently cloned CXC chemokine BRAK, which is ubiquitously expressed in normal tissue extracts but is absent from many tumor cell lines in vitro. To define the cell populations expressing BRAK in vivo, in situ mRNA hybridization was performed on normal and cancerous tissues from six different histological sites. The predominant normal cell type constitutively expressing BRAK in vivo was squamous epithelium. Expression in tumors was heterogeneous, with the majority of HNSCCs and some cervical squamous cell carcinomas (SCCs) showing loss of BRAK mRNA. Although absent in unstimulated peripheral blood mononuclear cells, high levels of BRAK were consistently found in infiltrating inflammatory cells (with lymphocyte morphology) in nearly all cancers examined. Furthermore, BRAK expression was demonstrated in B cells and monocytes, after stimulation of peripheral blood mononuclear cells with lipopolysaccharide. This study demonstrates for the first time up-regulation of BRAK mRNA by inflammatory cells in the tumor microenvironment and lost expression from certain cancers in vivo. The data suggest that BRAK may have a role in host-tumor interactions.

Expression of apoptosis-related genes in human head and neck squamous cell carcinomas undergoing p53-mediated programmed cell death.

Human head and neck squamous cell carcinoma (HNSCC) lines infected with a replication-defective Ad5CMV-p53 vector bearing a wild-type human p53 gene were used to examine alterations in the production of proteins implicated in regulating apoptosis. Because HNSCC lines express abundant levels of c-myc, and simultaneous expression of c-myc and p53 is known to trigger apoptosis in other cells, cooperation between these two genes was examined. Surprisingly, levels of c-myc mRNA and protein were rapidly and profoundly suppressed after infection with wild-type p53. Suppression of c-myc using antisense oligodeoxynucleotides (in the absence of p53) was sufficient to trigger apoptosis in Tu-138 cells, raising the possibility that the reduction of c-myc may be involved in at least one of the cell death pathways mediated by p53. Expression of a panel of Bcl-2 homology proteins was also examined in HNSCC lines undergoing p53-mediated apoptosis. No changes in Bcl-2, Bak, or Bcl-xS were found after p53 expression. Increased levels of the apoptosis-accelerating protein Bax were found in HNSCC lines after infection with Ad5CMV-p53. Induction of the apoptosis-inhibiting protein Bcl-xL was observed in Tu-167 cells and may account for the delayed onset of apoptosis in these cells. These studies suggest that multiple pathways may regulate apoptosis after transient overexpression of p53.

Bystander effect in the adenovirus-mediated wild-type p53 gene therapy model of human squamous cell carcinoma of the head and neck.

In models of human lung and head and neck cancer, there have been anecdotal reports of a bystander effect in wild-type p53 gene therapy, an apoptosis-inducing molecular intervention strategy. These reports do not definitively demonstrate the presence of a bystander effect, nor do they elucidate requirements for or characteristics of this phenomenon. We have investigated human squamous cell carcinoma of the head and neck for the presence and requirements of a bystander effect after wild-type p53 gene transduction. Recombinant adenovirus, Ad-p53, was used for wild-type p53 gene transfers. To investigate the role of intercellular contact between p53-transduced and nontransduced cells in mediating a growth inhibitory (bystander) effect on nontransduced cells, coculturing experiments were conducted on human squamous cell carcinoma of the head and neck cell lines TU138 and TU167. For TU138, 29% growth inhibition of nontransduced cells was demonstrated 3 days after p53-transduced and nontransduced cells were cocultured with intercellular contact. This growth inhibition was abolished when cells were cocultured without intercellular contact. TU167 did not demonstrate a bystander effect under any coculturing condition. Supernatant from Ad-p53-infected TU138 and TU167 cells demonstrated no growth-inhibitory effect on respective nontransduced cells. The bystander effect in the adenovirus-mediated wild-type p53 gene therapy model of squamous cell carcinoma of the head and neck, when present, requires intercellular contact. Possible mechanisms of the observed in vitro bystander effect are discussed.

Combination E2F-1 and p53 gene transfer does not enhance growth inhibition in human squamous cell carcinoma of the head and neck.

Ample data exist contending that wild-type p53 and E2F-1 cooperate to mediate apoptosis, that E2F-1-mediated apoptosis is p53 dependent in some situations, and that E2F-1 can induce accumulation of p53 in mammalian cells. These data support the investigation of the biological consequences of combined wild-typep53 and E2F-1 overexpression in human squamous cell carcinoma of the head and neck (SCCHN) for the purpose of developing apoptosis-inducing molecular intervention strategies for the management of this devastating disease. The recombinant adenovirus (Ad) vectors Ad-p53 and Ad-E2F-1 were used for wild-type p53 and E2F-1 gene transfers, respectively, into SCCHN cell lines TU138 and TU167. SCCHN cells transduced with either p53, E2F-1, or both underwent in vitro growth analysis, which revealed that simultaneous p53 and E2F-1 gene transfer did not result in enhanced growth inhibition. To explain our growth assay findings on the basis of potential negative molecular interactions between E2F-1 and p53, Western and Northern blotting analyses were performed to investigate the differential expression of the downstream p53-transactivated genes, p21Waf1 and BAX, under various p53 and E2F-1 gene transfer conditions. Whereas Western immunoblotting demonstrated that E2F-1 antagonized p53 induction of p21Waf1 and BAX, Northern blotting revealed that this interference was pretranslationally regulated and p53 dependent. Coimmunoprecipitation assay confirmed that the wild-type p53 and E2F-1 gene products formed protein-protein complexes in our cell lines. Our in vitro data demonstrated that in SCCHN, E2F-1 interferes with induction of p53-transactivated genes, probably through the formation of protein-protein complexes. Simultaneous p53 and E2F-1 gene transfer is not therapeutically advantageous in this in vitro model of SCCHN.

Protein tyrosine kinase inhibition blocks granule exocytosis and cytolytic function of lymphokine-activated killer cells.

Short-term pretreatment of human lymphokine-activated killer cells (LAK) with the protein tyrosine kinase-specific inhibitor Herbimycin A (Herb A) blocked cytotoxic function against the NK-resistant (LAK-sensitive) tumor targets, SK-Mel-1 (human melanoma) and Daudi (human lymphoma). Greater than 50% inhibition of LAK activity was observed after a 2.5-h pretreatment with 0.125 microgram/ml (ca. 0.2 microM) Herb A. Inhibition of LAK occurred over a time interval in which LAK were not dependent upon IL-2 for maintenance of killing function, supporting the conclusion that the drug interfered with mobilization of cytotoxic function. Conjugate formation between LAK and tumor targets was unaffected by Herb A, indicating that inhibition was occurring at a post-binding step. Granule exocytosis as measured by BLT-esterase release was detected from LAK after coincubation with tumor targets, and was inhibited by Herb A pretreatment. The majority of LAK killing was dependent upon extracellular calcium, supporting the hypothesis that granule exocytosis rather than Fas ligand was the principal pathway leading to target cell death. The data suggest that protein tyrosine kinases play a pivotal role in LAK cytolytic function by regulating granule exocytosis.

Tumor target binding induces phosphorylation of two M(r) 65,000 lymphokine-activated killer proteins.

Effector-target cell conjugate formation is an essential step during lymphokine-activated killer (LAK) cell-mediated cytotoxicity. Protein phosphorylation changes in human LAKs after contact with NK-resistant (LAK-sensitive) tumors were examined by two-dimensional SDS-PAGE. Exposure to either SK-Mel-1 (melanoma) or Raji (lymphoma) targets led to increased phosphorylation of two M(r) 65,000 LAK proteins, pp65a and pp65b, with isoelectric points of 5.1 and 5.2, respectively. Phosphorylation of both substrates was initiated between 1 and 5 min after coincubation with tumor targets. Contact between LAKs and targets was required for p65 phosphorylation because soluble tumor factors failed to induce phosphorylation. Normal peripheral blood lymphocyte targets, which are bound very poorly by LAKs and are resistant to killing, failed to induce LAK p65 phosphorylation. The broad protein kinase inhibitor staurosporine inhibited phosphorylation of pp65a and pp65b, supporting the hypothesis that activation of a LAK protein kinase leads to p65 phosphorylation. Cross-linking of CD16 (Fc gamma RIIIA), which mediates antibody-dependent cellular cytotoxicity in LAKs, also led to increased pp65a and pp65b phosphorylation. Collectively, these data provide correlative evidence that p65 phosphorylation may be involved in the cytolytic function of LAKs.

Characterization of the M(r) 65,000 lymphokine-activated killer proteins phosphorylated after tumor target binding: evidence that pp65a and pp65b are phosphorylated forms of L-plastin.

Contact between lymphokine-activated killer (LAK) cells and natural killer-resistant tumor targets SK-Mel-1 (human melanoma) or Raji (human lymphoma) stimulates phosphorylation of two M(r) 65,000 LAK proteins (pp65a and pp65b) with nearly identical isoelectric points. Phosphoamino acid analysis of pp65a and pp65b detected phosphorylation exclusively on serine residues. Phosphotyrosine could not be detected on either substrate after immunoblotting with an antiphosphotyrosine antibody, and herbimycin A treatment failed to inhibit p65 phosphorylation induced by target contact. However, phorbol myristate acetate treatment alone induced LAK pp65a and pp65b phosphorylation, suggesting phosphorylation may be mediated by protein kinase C or a protein kinase C-regulated kinase. The molecular weight and isoelectric points of pp65a and pp65b are similar to that reported for the human actin-bundling protein, L-plastin (L-fimbrin). On two-dimensional SDS-PAGE gel immunoblots, a peptide specific anti-L-plastin antiserum bound to pp65a and pp65b, suggesting that the phosphoproteins are similar or identical to L-plastin. In addition, two adjacent M(r) 65,000 LAK proteins were also detected by the antiserum and may correspond to unphosphorylated forms of L-plastin. On the basis of known properties of phosphorylated L-plastin, it is hypothesized that p65 phosphorylation in LAKs may regulate adhesion to tumor targets.

Colombian emigration: a research note on its probable quantitative extent.

"This note has two objectives. One is to provide a brief overview of quantitative estimates of Colombian emigration, including formal attempts to estimate the volume of net emigration. The second objective is to update the existing estimates with more recent data (in a highly speculative fashion)."