Relations among expression of CXCR4, histological patterns, and metastatic potential in adenoid cystic carcinoma of the head and neck

Adenoid cystic carcinoma (ACC) may acquire a chemokine-mediated mechanism during the process of metastasis. To investigate the involvement of chemokines in metastasis from ACC, expression of CXCR4 in surgical specimens of ACC and two tumor lines transplantable to nude mice was examined immunohistochemically. In addition, the expression levels of CXCR4 protein and mRNA were examined by Western blotting and reverse-transcription polymerase chain reaction. Our results showed that patients whose tumors expressed high levels of CXCR4 had metastases to the regional lymph nodes and the lung, resulting in poor outcomes. ACCs showing a solid or cribriform pattern with distant metastasis were strongly positive for CXCR4, while those showing a tubular or cribriform pattern without metastasis were weakly positive for CXCR4. In the in vivo model, ACCY tumor showed increasing expression levels of CXCR4 with tumor growth, and the histological pattern changed from cribriform to solid. The histological pattern of ACCI, associated with spontaneous metastasis to the neck, changed from cribriform to undifferentiated carcinoma and was highly metastatic to the lung. This tumor showed high levels of CXCR4 protein and mRNA. These results suggest that CXCR4 expression, histological patterns, and metastatic potential are closely related in ACC.

In vitro susceptibility to anticancer agents of the human KB carcinoma cell line transfected with COX-2 cDNA

In order to investigate the malignant phenotype of cyclooxygenase (COX)-2 overexpressing cancer cells, a human epidermoid KB carcinoma cell line minimally expressing COX-2 protein was transfected with human COX-2 cDNA. In this study, we used a COX-2 transfected clone KB/COX-2 and a neomycin-transfected clone KB/neo as the control. When we examined the susceptibility to anticancer agents, there was no difference between these two clones in vincristine, bleomycin and 5-fluorouracil, although KB/COX-2 showed a 2.5-fold resistance to cisplatin (CDDP) as compared with KB/neo. The IC50 for CDDP was 4.3 microM in KB/COX-2 and 1.7 microM in KB/neo. Treatment with small interfering RNA (siRNA) mediated the inhibition of COX-2 significantly increasing the level of susceptibility to CDDP in COX-2 siRNA as compared to that of the control siRNA. The expression of MRP1 and MRP2 was stronger in KB/COX-2 than in KB/neo by Western blot analysis. In addition, apoptosis induction by CDDP was at a lower level in KB/COX-2 (31%) than in KB/neo (38%). These results suggested that the overexpression of COX-2 increases the intracellular production of MRP1 and MRP2 and causes drug resistance to CDDP.

[Long term outcome of arterial switch surgery for transposition of the great arteries: evaluation of the reconstruction of the pulmonary artery]

We assessed the effect of reconstructing the pulmonary artery during arterial switch surgery for transposition of the great arteries on late pulmonary stenosis. Sixty-five patients who underwent Lecompte procedure between September 1991 and December 2006 were divided, by the procedure used chronologically to reconstruct the pulmonary artery, into group XP (single pantaloon patch with equine pericardium, n = 11), group P (direct reconstruction, n = 47), and group AP (single pantaloon patch with fresh autopericardium, n = 7). Outcome and pulmonary stenosis on the most recent ultrasound cardiography (UCG) were compared in the 3 groups. The median follow-up was 13, 7.5, and 1.3 years, respectively. Both early and late mortalities were 1.5% (1/65). Although percutaneous trans-pulmonary angioplasty was necessary in 1, 13, and 3 patients, there was 1, 1, and 0 reoperation for pulmonary stenosis in the 3 groups, respectively. Pulmonary stenosis (pulmonary arterial maximum flow velocity > 3 m/sec on UCG) was present in 4 (40%). 14 (30%). and 3 patients (43%). Although there was no significant difference among the 3 procedures in preventing pulmonary stenosis 10 years after arterial switch surgery, direct reconstruction of the pulmonary artery may show a superior outcome, in particular, over 10 years after arterial switch surgery.

Prognostic significance of cyclooxygenase-2 and DNA topoisomerase IIalpha expression in oral carcinoma

BACKGROUND

Despite recent advances in the diagnosis and treatment of oral carcinoma, outcomes remain disappointing. The identification of new prognostic factors is necessary to improve survival. To determine the prognostic significance of cyclooxygenase (COX)-2 and DNA topoisomerase (DNA-Topo) IIalpha expression in patients with oral carcinoma, we immunohistochemically examined these enzymes and studied their relation to overall 5-year survival.

METHODS

Surgical specimens were obtained from 160 patients with oral carcinoma, 80 with and 80 without regional lymph node metastasis. The specimens were immunostained for COX-2 and DNA-Topo IIalpha as an index of cell proliferative activity. COX-2 immunoreactivity and clinicopathological data were analyzed, and 5-year survival was calculated by the Kaplan-Meier method.

RESULTS

COX-2 expression in primary lesions was higher in cases with lymph node metastasis than in those without lymph node metastasis. An increase in tumor size was associated with increased COX-2 expression. In most cases with lymph node metastasis, COX-2 expression was higher in metastatic lesions than in primary lesions. As COX-2 expression increased, the DNA-Topo IIalpha labeling index significantly increased and the overall 5-year survival rate decreased.

CONCLUSION

Expression of COX-2 and DNA-Topo IIalpha were related to lymph node metastasis, cell proliferative activity, and overall 5-year survival rate in oral carcinoma. These enzymes may therefore be valuable diagnostic and prognostic indices in oral carcinoma.

Neuroblastoma presenting with dilated cardiomyopathy

We report an infant with neuroblastoma who presented with dilated cardiomyopathy. A 3-month-old girl presented with dilated cardiomyopathy diagnosed as stage III neuroblastoma. Since total resection was impossible, chemotherapy was started. Cardiomyopathy was normalized by improvement of neuroblastoma. The prompt improvement of cardiac function following treatment of neuroblastoma suggested that cardiomyopathy in this patient was caused by the increase in catecholamines secreted by neuroblastoma and that reduction in catecholamines by treatment of neuroblastoma led to improvement in the cardiomyopathy.

Two-dimensional pattern reverse Monte Carlo method for modelling the structures of nano-particles in uniaxial elongated rubbers

Two-dimensional pattern reverse Monte Carlo (2D pattern RMC) analysis is performed to model the structures of nano-particles in uniaxially elongated rubbers using two-dimensional patterns of structure factor of the nano-particles obtained by time-resolved two-dimensional ultra-small angle x-ray scattering. Four spot patterns are observed for a large elongation ratio and the shapes change with increasing elongation ratio. We performed the 2D pattern RMC method for the uniaxial system in order to make a model of the structures from the two-dimensional structure factors. The preliminary results of the 2D pattern RMC analysis of the two-dimensional structure factors of silica particles in a uniaxially elongated styrene-butadiene rubber are presented.

CD44+/CD24- breast cancer cells exhibit enhanced invasive properties: an early step necessary for metastasis

Introduction

A subpopulation (CD44⁺/CD24^-) of breast cancer cells has been reported to have stem/progenitor cell properties. The aim of this study was to investigate whether this subpopulation of cancer cells has the unique ability to invade, home, and proliferate at sites of metastasis.

Methods

CD44 and CD24 expression was determined by flow cytometry. Northern blotting was used to determine the expression of proinvasive and 'bone and lung metastasis signature' genes. A matrigel invasion assay and intracardiac inoculation into nude mice were used to evaluate invasion, and homing and proliferation at sites of metastasis, respectively.

Results

Five among 13 breast cancer cell lines examined (MDA-MB-231, MDA-MB-436, Hs578T, SUM1315, and HBL-100) contained a higher percentage (>30%) of CD44⁺/CD24^- cells. Cell lines with high CD44⁺/CD24^- cell numbers express basal/mesenchymal or myoepithelial but not luminal markers. Expression levels of proinvasive genes (IL-1α, IL-6, IL-8, and urokinase plasminogen activator [UPA]) were higher in cell lines with a significant CD44⁺/CD24^- population than in other cell lines. Among the CD44⁺/CD24^--positive cell lines, MDA-MB-231 has the unique property of expressing a broad range of genes that favor bone and lung metastasis. Consistent with previous studies in nude mice, cell lines with CD44⁺/CD24^- subpopulation were more invasive than other cell lines. However, only a subset of CD44⁺/CD24^--positive cell lines was able to home and proliferate in lungs.

Conclusion

Breast cancer cells with CD44⁺/CD24^- subpopulation express higher levels of proinvasive genes and have highly invasive properties. However, this phenotype is not sufficient to predict capacity for pulmonary metastasis.

Effects of HIV protease inhibitor ritonavir on Akt-regulated cell proliferation in breast cancer

PURPOSE

These studies were designed to determine whether ritonavir inhibits breast cancer in vitro and in vivo and, if so, how.

EXPERIMENTAL DESIGN

Ritonavir effects on breast cancer cell growth were studied in the estrogen receptor (ER)-positive lines MCF7 and T47D and in the ER-negative lines MDA-MB-436 and MDA-MB-231. Effects of ritonavir on Rb-regulated and Akt-mediated cell proliferation were studied. Ritonavir was tested for inhibition of a mammary carcinoma xenograft.

RESULTS

ER-positive estradiol-dependent lines (IC50, 12-24 micromol/L) and ER-negative (IC50, 45 micromol/L) lines exhibit ritonavir sensitivity. Ritonavir depletes ER-alpha levels notably in ER-positive lines. Ritonavir causes G1 arrest, depletes cyclin-dependent kinases 2, 4, and 6 and cyclin D1 but not cyclin E, and depletes phosphorylated Rb and Ser473 Akt. Ritonavir induces apoptosis independent of G1 arrest, inhibiting growth of cells that have passed the G1 checkpoint. Myristoyl-Akt, but not activated K-Ras, rescues ritonavir inhibition. Ritonavir inhibited a MDA-MB-231 xenograft and intratumoral Akt activity at a clinically attainable serum Cmax of 22 +/- 8 micromol/L. Because heat shock protein 90 (Hsp90) substrates are depleted by ritonavir, ritonavir effects on Hsp90 were tested. Ritonavir binds Hsp90 (K(D), 7.8 micromol/L) and partially inhibits its chaperone function. Ritonavir blocks association of Hsp90 with Akt and, with sustained exposure, notably depletes Hsp90. Stably expressed Hsp90alpha short hairpin RNA also depletes Hsp90, inhibiting proliferation and sensitizing breast cancer cells to low ritonavir concentrations.

CONCLUSIONS

Ritonavir inhibits breast cancer growth in part by inhibiting Hsp90 substrates, including Akt. Ritonavir may be of interest for breast cancer therapeutics and its efficacy may be increased by sustained exposure or Hsp90 RNA interference.

Elevated cell migration, invasion and tumorigenicity in human KB carcinoma cells transfected with COX-2 cDNA

In order to investigate the involvement of cyclooxygenase (COX)-2 in cell growth and invasion of oral cancer, a human epidermoid carcinoma cell line KB minimally expressing COX-2 protein was transfected with COX-2 cDNA and these activities were compared with mock-transfected KB in vitro and in vivo. KB/COX-2 clones showed a similar growth rate in vitro compared to KB/neo clones, but demonstrated significantly increased PGE2 production, cell migration and invasion. These KB/COX-2 clones markedly expressed MMP-9, pro-MMP-2 and activated-MMP-2 as compared to KB/neo clones in gelatin zymography. Western blot analysis showed that expression of MT1-MMP, Rho and Rac 1 in KB/COX-2 clones were stronger than that in KB/neo clones, but expression of TIMP-1 and TIMP-2 were weaker in KB/COX-2 clones than in KB/neo clones. When these cells were inoculated subcutaneously into nude mice, tumorigenicity and tumor growth were significantly elevated in KB/COX-2 tumors than in KB/neo tumors, and the gelatinase activity was much stronger in KB/COX-2 tumor tissues than in KB/neo tumor tissues in film in situ zymography. The orthotopic inoculation of cells to the oral floor showed that local invasion was pronounced in KB/COX-2 tumors. These results indicated that overexpression of COX-2 elevated tumorigenicity, tumor growth and invasion of human KB carcinoma cells via up-regulated MMP and Rho family small GTPases and down-regulated TIMP activities.

The p160 family coactivators regulate breast cancer cell proliferation and invasion through autocrine/paracrine activity of SDF-1alpha/CXCL12

Estrogen receptors (ERs) regulate the transcription of genes involved in breast cancer cell proliferation, invasion and metastasis. In addition to ligand concentration, phosphorylation and coactivator/corepressor levels control ER-dependent transcription. In this study, we used MCF-7 breast cancer sublines with variable levels of the steroid receptor coactivator 1 (SRC-1) to investigate the importance of coactivator levels in basal and estrogen-inducible expression of SDF-1alpha/CXCL12, cathepsin D and cMyc. Basal expression of SDF-1alpha and cMyc but not of cathepsin D was substantially lower in a MCF-7 subline lacking SRC-1 ((MCF-7/p2) compared with MCF-7 sublines expressing SRC-1 (MCF-7/p1 and LCC2). Although estrogen efficiently induced SDF-1alpha in MCF-7/p1 cells, very little induction of this gene was observed in MCF-7/p2 cells. The absence of SRC-1 had no effect on estrogen-inducible expression cMyc and cathepsin D suggesting that coactivator levels determine the expression of only a subset of estrogen-regulated genes. Introduction of SRC-1, SRC-2/TIF-2 or SRC-3/AIB1 increased basal expression of SDF-1alpha in MCF-7/p2 cells. Consistent with the role of SDF-1alpha in mediating estrogen-induced proliferation, estrogen failed to increase proliferation of MCF-7/p2 cells. In matrigel invasion assays, conditioned media from MCF-7/p1 but not MCF-7/p2 cells increased invasion of cancer cells expressing metastasis-associated genes and CXCR4, the receptor for SDF-1alpha. These results suggest that coactivators control SDF-1alpha expression, which mediates estrogen-induced proliferation and invasion through autocrine and paracrine mechanisms, respectively. These results also provide a molecular explanation for recent observations linking co-overexpression of coactivators and her2/neu with poor prognosis: coactivators increase SDF-1alpha expression whereas her2/neu stabilize CXCR4 protein.

Changes of histological and biological features by serial passages in a human adenoid cystic carcinoma line transplantable in nude mice

The basic histologic patterns of adenoid cystic carcinoma (ACC) are classified into three types (tubular, cribriform and solid), but clinical significance of the histological type is unclear. We have successfully established a human tumor line derived from ACC that is serially transplantable in nude mice. This tumor showed an increased growth rate as the passage levels proceeded, and the histological type was changed from a cribriform pattern in the initial stage to a solid one. In this study, we investigated the relationship between histological type and biological characteristics by analyzing the serially transplantable ACC tumor model. As a result, the tumor growth rate at the 15th passage level was increased approximately 5-fold compared with that at the initial passage level. In the histological type, approximately 30% of the cribriform pattern in the initial level was changed to a solid one at the 15th passage level, and the PCNA labeling index was elevated 4-fold. Concomitant with this, expression of Ki-67, p53 and bcl-2 proteins was increased, and apoptotic cells were decreased as demonstrated by the TUNEL method. From these findings, it was suggested that cell proliferation and histological change of this ACC tumor are related to the inhibition of apoptosis. This tumor line would provide a useful model for investigating the biological behavior of ACC.

Promotion of cell differentiation, and suppression of cell growth and cyclooxygenase-2 expression by differentiation-inducing agents in human oral squamous carcinoma SCC25 cells

We investigated the relationship between cell growth and differentiation and COX-2 expression in oral squamous cell carcinoma (SCC) in vitro and in vivo. Treatment of SCC25 oral squamous carcinoma cells with sodium butyrate (SB) at 0.5-5 mM or all-trans retinoic acid (ATRA) at 3-300 microM inhibited cell growth and induced apoptosis in a dose-dependent manner with concomittant increases in expression of keratin 13, p21WAF1/Cip1 and p27Kip1 and decreases in expression of COX-2. These effects were more pronounced with SB than with ATRA. Injection of SB or ATRA near SCC25-derived tumors in nude mice resulted in inhibition of growth and elevation of differentiation of the tumor accompanied by marked keratinization and increased expression of keratin 13 and decreased expression of COX-2. These results show that the differentiation-inducing agents, particularly SB, suppress growth of oral squamous carcinoma cells through apoptosis and induce cell differentiation possibly through mechanisms involving COX-2, p27Kip1 and/or p21WAF1/Cip1 in vitro and in vivo.

The macrophage inhibitory cytokine integrates AKT/PKB and MAP kinase signaling pathways in breast cancer cells

Macrophage inhibitory cytokine 1 (MIC-1), a divergent member of the transforming growth factor beta superfamily, plays a role in the progression of a number of cancers, including breast, gastric, prostate and colorectal carcinomas. Serum MIC-1 levels are elevated in patients with metastatic prostate, breast and colorectal carcinomas. In vitro studies have revealed a cell type-specific role for MIC-1 in senescence and apoptosis. MIC-1 activates the survival kinase AKT/PKB in neuronal cells. Depending on the cell type, it activates or represses the MAP kinases ERK1/2. Mechanisms responsible for an increased MIC-1 expression in cancers and the consequences of MIC-1 overexpression, however, are not known. In this study, we show that AKT/PKB directly regulates the expression of MIC-1 in breast cancer cells. Sequences within -88 to +30 of the MIC-1 promoter are required for the AKT-mediated induction of MIC-1. This region of the promoter contains two SP-1 binding sites (SP-1B and SP-1C), which bind to the SP-1 and SP-3 proteins. Mutation of SP-1C but not SP-1B reduced the AKT-mediated activation of MIC-1. MIC-1 increased the basal ERK1 phosphorylation and prolonged the estrogen-stimulated ERK1 phosphorylation in MCF-7 breast cancer cells without altering the phosphorylation status of AKT/PKB. Immunohistochemistry with MIC-1 antibody revealed an MIC-1 expression within the cancer cells of primary breast cancer and in the MCF-7 xenografts. Furthermore, a limited analysis of RNA from primary breast cancers revealed an overexpression of MIC-1 in tumors, compared with normal tissues. These results suggest that AKT/PKB through MIC-1 could regulate the ERK1 activity and the MIC-1 expression levels may serve as a surrogate marker for the AKT activation in tumors.

Establishment of a new cell line with neuronal differentiation derived from small cell neuroendocrine carcinoma of the maxillary sinus

OBJECTIVE

It is well known that small cell neuroendocrine carcinoma (SNEC) arising at extrapulmonary sites has a poor prognosis and an interesting biological characterization. To understand biological characterization and elucidation of the origin of the histogenesis of SNEC, we report the establishment of a new SNEC cell line and characteristics of neuroendocrine properties including neuronal differentiation by treatment with dibutyryl cyclic AMP (db-cAMP).

METHODS

We established a new cell line (SNEC-MI) derived from SNEC of the maxillary sinus by a modified spill-out method, and verified neuroendocrine properties including neuronal differentiation by immunocytochemical and immunoblotting methods.

RESULTS

The established cell line showed spherical or spindle shape in monolayer culture and was positive for neuron-specific enolase (NSE), neuronal cell adhesion protein (N-CAM, CD56) and gastrin-releasing peptide. NSE was also demonstrated in the cultured medium and dense-core neuroendocrine granules were detected ultrastructurally in the cytoplasm. Treatment of cells with db-cAMP markedly induced the development and elongation of neuronal processes, which formed a netlike arrangement. Characterization of these elongated neuronal processes revealed them immunoreacting intensely with high molecular-weight neurofilament, and a time-dependent increase of microtubule-associated protein-2 in cell lysates.

CONCLUSIONS

These findings indicated that this cell line possesses the capability to differentiate into neuronal cells, and supported the hypothesis that extrapulmonary SNEC might be derived from a pluripotent stem cell.