BRAK/CXCL14 is a CXC chemokine constitutively expressed at the mRNA level in certain normal tissues but absent from many established tumor cell lines and human cancers. Although multiple investigators cloned BRAK, little is known regarding the physiologic function of BRAK or the reason for decreased expression in cancer. To understand the possible significance associated with loss of BRAK mRNA in tumors, we examined the pattern of BRAK protein expression in normal and tumor specimens from patients with squamous cell carcinoma (SCC) of the tongue and used recombinant BRAK (rBRAK) to investigate potential biological functions. Using a peptide-specific antiserum, abundant expression of BRAK protein was found in suprabasal layers of normal tongue mucosa but consistently was absent in tongue SCC. Consistent with previous in situ mRNA studies, BRAK protein also was expressed strongly by stromal cells adjacent to tumors. In the rat corneal micropocket assay, BRAK was a potent inhibitor of in vivo angiogenesis stimulated by multiple angiogenic factors, including interleukin 8, basic fibroblast growth factor, and vascular endothelial growth factor. In vitro, rBRAK blocked endothelial cell chemotaxis at concentrations as low as 1 nmol/L, suggesting this was a major mechanism for angiogenesis inhibition. Although only low affinity receptors for BRAK could be found on endothelial cells, human immature monocyte-derived dendritic cells (iDCs) bound rBRAK with high affinity (i.e., K d , ϳ2 nmol/L). Furthermore, rBRAK was chemotactic for iDCs at concentrations ranging from 1 to 10 nmol/L. Our findings support a hypothesis that loss of BRAK expression from tumors may facilitate neovascularization and possibly contributes to immunologic escape.

Using differential display and microarray analysis, we have identified and confirmed the differential expression of 9 genes in HNSCC. Work is in progress to determine the biological significance of these genes and their potential as biomarkers or targets for therapy.

Supplementary Figure 1 from BRAK/CXCL14 Is a Potent Inhibitor of Angiogenesis and a Chemotactic Factor for Immature Dendritic Cells

Supplementary Figure 1 from BRAK/CXCL14 Is a Potent Inhibitor of Angiogenesis and a Chemotactic Factor for Immature Dendritic Cells

<div>Abstract<p>BRAK/CXCL14 is a CXC chemokine constitutively expressed at the mRNA level in certain normal tissues but absent from many established tumor cell lines and human cancers. Although multiple investigators cloned BRAK, little is known regarding the physiologic function of BRAK or the reason for decreased expression in cancer. To understand the possible significance associated with loss of BRAK mRNA in tumors, we examined the pattern of BRAK protein expression in normal and tumor specimens from patients with squamous cell carcinoma (SCC) of the tongue and used recombinant BRAK (rBRAK) to investigate potential biological functions. Using a peptide-specific antiserum, abundant expression of BRAK protein was found in suprabasal layers of normal tongue mucosa but consistently was absent in tongue SCC. Consistent with previous <i>in situ</i> mRNA studies, BRAK protein also was expressed strongly by stromal cells adjacent to tumors. In the rat corneal micropocket assay, BRAK was a potent inhibitor of <i>in vivo</i> angiogenesis stimulated by multiple angiogenic factors, including interleukin 8, basic fibroblast growth factor, and vascular endothelial growth factor. <i>In vitro</i>, rBRAK blocked endothelial cell chemotaxis at concentrations as low as 1 nmol/L, suggesting this was a major mechanism for angiogenesis inhibition. Although only low affinity receptors for BRAK could be found on endothelial cells, human immature monocyte-derived dendritic cells (iDCs) bound rBRAK with high affinity (<i>i.e., K</i>_d, ∼2 nmol/L). Furthermore, rBRAK was chemotactic for iDCs at concentrations ranging from 1 to 10 nmol/L. Our findings support a hypothesis that loss of BRAK expression from tumors may facilitate neovascularization and possibly contributes to immunologic escape.</p></div>

<div>Abstract<p>BRAK/CXCL14 is a CXC chemokine constitutively expressed at the mRNA level in certain normal tissues but absent from many established tumor cell lines and human cancers. Although multiple investigators cloned BRAK, little is known regarding the physiologic function of BRAK or the reason for decreased expression in cancer. To understand the possible significance associated with loss of BRAK mRNA in tumors, we examined the pattern of BRAK protein expression in normal and tumor specimens from patients with squamous cell carcinoma (SCC) of the tongue and used recombinant BRAK (rBRAK) to investigate potential biological functions. Using a peptide-specific antiserum, abundant expression of BRAK protein was found in suprabasal layers of normal tongue mucosa but consistently was absent in tongue SCC. Consistent with previous <i>in situ</i> mRNA studies, BRAK protein also was expressed strongly by stromal cells adjacent to tumors. In the rat corneal micropocket assay, BRAK was a potent inhibitor of <i>in vivo</i> angiogenesis stimulated by multiple angiogenic factors, including interleukin 8, basic fibroblast growth factor, and vascular endothelial growth factor. <i>In vitro</i>, rBRAK blocked endothelial cell chemotaxis at concentrations as low as 1 nmol/L, suggesting this was a major mechanism for angiogenesis inhibition. Although only low affinity receptors for BRAK could be found on endothelial cells, human immature monocyte-derived dendritic cells (iDCs) bound rBRAK with high affinity (<i>i.e., K</i>_d, ∼2 nmol/L). Furthermore, rBRAK was chemotactic for iDCs at concentrations ranging from 1 to 10 nmol/L. Our findings support a hypothesis that loss of BRAK expression from tumors may facilitate neovascularization and possibly contributes to immunologic escape.</p></div>

Vestibular decruitment (VD) is a paradoxical response to stimulation of the ear with the 2 strengths of the Torok monothermal caloric test. The culmination frequency (CF) value of the weaker of the 2 stimuli is equal to or greater than the strong stimulus response. Vestibular decruitment has been shown to be associated with brain stem and cerebellar lesions. However, the underlying neurophysiology of VD is not known. The purpose of this study is to attempt an understanding of VD by analyzing the CF values obtained from a normal group of subjects and comparing the results from a patient cohort who had MRI confirmed brain stem/cerebel!ar lesions.Methods: From our database of patients, we randomly selected 70 patients who had both MRI-confirmed posterior fossa lesions and VD. In 35 patients VD was unilateral, and in the rest it was bilateral. Normative data were obtained prospectively from 27 patients. The CF values from each of these groups were statistically compared and analyzed.Results: Patients with bilateral VD displayed an average CF of 40.9 with the 10-mL stimulus and 40.6 with the 100-mL stimulus. The latter values showed no statistical difference from CF values of normal subjects. However the 10-mL CF values in patients were significantly higher than CF values of normal subjects. Statistical analysis of CF values of unilateral VD showed similar results.Conclustion: Although this study does not explain the underlying neurophysiological mechanisms of VD, statistical analysis of the data shows that in VD it is an increase in the weaker stimulus CF value that results in the paradoxical response rather than a decrease in the strong stimulus responses. This information could form the basis for further experimental studies.