Isolation and Characterization of Cancer Stem Cells from Primary Head and Neck Squamous Cell Carcinoma Tumors.

Drug resistance remains a significant problem in the treatment of patients with head and neck squamous cell carcinoma (HNSCC). Recent reports showed that a subpopulation of highly tumorigenic cells, called cancer stem cells (CSCs), is uniquely resistant to chemotherapy, suggesting that these cells play an important role in the relapse of HNSCC. The development of methods for the isolation and culture of cancer stem cells is a key step to enable studies exploring the mechanisms underlying the role of these cells in chemoresistance. Here, we describe a method to isolate cancer stem cells from primary head and neck tumors and for the generation of orospheres.

The effect of a sequential compression device on hemodynamics in arthroscopic shoulder surgery using beach-chair position.

PURPOSE: This study investigated the effect of intermittent compression by a sequential compression device (SCD) on the incidence of hypotension and other hemodynamic variables in the beach-chair position. METHODS: Fifty healthy patients undergoing elective shoulder arthroscopy under general anesthesia were randomly assigned to either the control group (n = 25) or SCD group (n = 25). A standardized protocol for pre-hydration and anesthetic technique was followed. Hemodynamic variables were measured before (pre-induction values) and 5 minutes after the induction of anesthesia in the supine position (baseline values) and 1, 3, and 5 minutes after the patient was raised to a 70 degrees sitting position. The incidence of hypotension was recorded and treated with ephedrine. RESULTS: The incidence of hypotension was significantly higher in the control group (16 of 25) than that in the SCD group (7 of 25) (P = .022; odds ratio, 0.219; 95% confidence interval, 0.066 to 0.723). Between the groups, mean arterial pressure, cardiac index, and stroke volume index were significantly higher in the SCD group compared with values in the control group at 1 minute after patients were raised to a 70 degrees sitting position (P = .035, P = .046, and P = .011, respectively). CONCLUSIONS: This study showed that the use of an SCD could reduce the incidence of hypotension from 64% to 28% and supports hemodynamic variables such as mean arterial pressure and stroke volume index when patients were changed from the supine to the beach-chair position in those undergoing shoulder arthroscopy. LEVEL OF EVIDENCE: Level I, therapeutic randomized controlled trial.

Pathogenicity of a disease-associated human IL-4 receptor allele in experimental asthma.

Polymorphisms in the interleukin-4 receptor alpha chain (IL-4R alpha) have been linked to asthma incidence and severity, but a causal relationship has remained uncertain. In particular, a glutamine to arginine substitution at position 576 (Q576R) of IL-4R alpha has been associated with severe asthma, especially in African Americans. We show that mice carrying the Q576R polymorphism exhibited intense allergen-induced airway inflammation and remodeling. The Q576R polymorphism did not affect proximal signal transducer and activator of transcription (STAT) 6 activation, but synergized with STAT6 in a gene target- and tissue-specific manner to mediate heightened expression of a subset of IL-4- and IL-13-responsive genes involved in allergic inflammation. Our findings indicate that the Q576R polymorphism directly promotes asthma in carrier populations by selectively augmenting IL-4R alpha-dependent signaling.

EGCG blocks tumor promoter-induced MMP-9 expression via suppression of MAPK and AP-1 activation in human gastric AGS cells.

Overexpression of matrix metalloproteinases (MMPs) has been known to correlate closely with tumor cell invasion and strategies to down-regulate their expression may ultimately be of clinical utility. In this study, we investigated the effects of (-)-epigallocatechin gallate (EGCG), a major green tea catechin, on the cell invasiveness and MMP-9 induction in human gastric cancer AGS cells. EGCG inhibited the phorbol 12-myristate 13-acetate (PMA)-induced cell invasiveness and MMP-9 expression in a dose-dependent manner. EGCG treatment was found to reduce the MMP-9 transcriptional activity. To further study the mechanisms for the EGCG-mediated regulation of MMP-9, the effects of EGCG on transcription factor AP-1 and mitogen-activated protein kinase (MAPK) activities were examined. The results showed that EGCG suppressed the PMA-induced AP-1 activation. EGCG also abrogated the PMA-induced activation of extracellular-regulated protein kinase (Erk) and c-jun N-terminal kinase (JNK), which are upstream modulators of AP-1. These results suggest that EGCG may exert at least part of its anti-invasive effect in gastric cancer by controlling MMP expression through the suppression of MAPK and AP-1 activation.

P38 MAPK pathway is involved in the urokinase plasminogen activator expression in human gastric SNU-638 cells.

Overexpression of urokinase plasminogen activator (uPA) is known to correlate closely with tumor cell invasion and metastasis. In gastric cancer, however, the mechanism for induction of uPA remains to be elucidated. In this study, we investigated the intracellular signaling for uPA expression in human gastric carcinoma cells (AGS, SNU-1, SNU-5, and SNU-638). SNU-638 cells which expressed a high level of uPA was found to be highly invasive on a matrigel, while AGS, SNU-1, and SNU-5 cells with low levels of uPA expression were only slightly invasive. SNU-638 cells showed a much higher P38 MAPK activity than the 3 other cell lines. However, there was no significant difference in the activities of P44/42 MAPK (Erk-1/2), JNK and Akt among the above cell lines. Treatment of SNU-638 cells with SB203580, a specific P38 MAPK inhibitor, reduced both the promoter activity and mRNA expression of uPA. Expression of a vector encoding a mutated-type P38alpha MAPK resulted in decrease in the uPA promoter activity in SNU-638 cells. These results suggest that P38 MAPK signaling pathway is important for uPA expression in gastric SNU-638 cells by enhancing the promoter activity of uPA.

Induction of apoptosis by the green tea flavonol (-)-epigallocatechin-3-gallate in human endothelial ECV 304 cells.

We have previously shown that treatment with (-)-epigallocatechin-3-gallate (EGCG) inhibited vascularity and tumor growth in human colon cancer xenografts in nude mice (Jung et al: Br J Cancer 84, 2001). In this study, we examined whether endothelial cell death by EGCG is mediated by apoptosis and which molecular mechanisms are involved in this process. EGCG was found to suppress cell growth and induce apoptosis largely through mitochondrial depolarization, activation of caspase-3 and cleavage of DNA fragmentation factor-45 in human endothelial ECV 304 cells. The induction of apoptosis by EGCG was confirmed by cleaved and condensed nuclear chromatin and DNA hypoploidy. These results suggest that EGCG may exert at least part of its anticancer effect by inhibiting angiogenesis through inducing endothelial apoptosis.