Increased expression of CD24 is associated with tumor progression and prognosis in patients suffering osteosarcoma

OBJECTIVE

As a small heavily glycosylated mucin-like glycosyl-phosphatidylinositol-anchored cell surface protein, CD24 plays an important role in carcinogenesis of various human malignancies. However, its involvement in osteosarcoma is still unclear. The aim of this study was to investigate the expression pattern and the clinical significance of CD24 in human osteosarcoma.

METHODS

CD24 mRNA and protein expression levels were, respectively, detected by RT-PCR and Western blot assays using 30 pairs of osteosarcoma and noncancerous bone tissues. Then, immunohistochemistry was performed to analyze the association of CD24 expression in 166 osteosarcoma tissues with clinicopathological factors or survival of patients.

RESULTS

CD24 expression at mRNA and protein levels were both significantly higher in osteosarcoma tissues than those in corresponding noncancerous bone tissues (both P < 0.001). In addition, CD24 protein was positively expressed in 129 of 166 (77.7 %) osteosarcoma specimens with a cytoplasmic and membraneous staining, and also increased in the osteosarcoma specimens with advanced clinical stage (P = 0.01) and positive distant metastasis (P = 0.005). The univariate and multivariate analyses showed that osteosarcoma patients with high CD24 expression had poorer overall and disease-free survival, and high CD24 expression was an independent prognostic factor for both overall and disease-free survival.

CONCLUSION

The aforementioned findings offer convincing evidence for the first time that the increased expression of CD24 is correlated with tumor aggressiveness and tumor metastasis of osteosarcoma, and this molecule is an independent prognostic marker for osteosarcoma patients.

A Potent and Orally Efficacious, Hydroxyethylamine-Based Inhibitor of β-Secretase

β-Secretase inhibitors are potentially disease-modifying treatments for Alzheimer's disease. Previous efforts in our laboratory have resulted in hydroxyethylamine-derived inhibitors such as 1 with low nanomolar potency against β-site amyloid precursor protein cleaving enzyme (BACE). When dosed intravenously, compound 1 was also shown to significantly reduce Aβ40 levels in plasma, brain, and cerebral spinal fluid. Herein, we report further optimizations that led to the discovery of inhibitor 16 as a novel, potent, and orally efficacious BACE inhibitor.

Comparative study of different surgical transposition methods for ulnar nerve entrapment at the elbow

This study compared the therapeutic effects of two techniques for surgical decompression treatment for ulnar nerve entrapment at the elbow: subcutaneous transposition and modified submuscular transposition with Z-lengthening of the pronator teres origin. A total of 278 patients with ulnar nerve entrapment (McGowan grades I - III) were randomly assigned to undergo one of these techniques. All patients were followed-up for 2 years. The effects were assessed by preoperative and postoperative cross-sectional area, motor conduction velocity, sensory conduction velocity and nerve action potential. All of these parameters improved after surgery in both groups. For patients with grade I disease, there were no significant differences between the two techniques. For patients with grade II and III disease, modified submuscular transposition was associated with significantly greater improvements compared with subcutaneous transposition. In conclusion, subcutaneous ulnar nerve transposition is recommended for grade I patients and modified submuscular ulnar nerve transposition for grade II and III patients.

SAR, cardiac myocytes protection activity and 3D-QSAR studies of salubrinal and its potent derivatives

Salubrinal is a selective inhibitor of endoplasmic reticulum (ER) stress and affords remarkable protection to cardiomyocytes. By studying the structure-activity relationship (SAR) of salubrinal, it was found that modification of the quinoline ring terminus and thiourea unit could confer the compound PP1-24 with markedly enhanced cardioprotective activity (EC50 ≤ 0.3 μM) that is 50-fold more potent than salubrinal. Comparative molecular field analysis (CoMFA) was performed using the obtained biological data and resulted in a statistically significant CoMFA model with high predictive power (q2 = 0.741, r2 = 0.991).

Trichosanthin-stimulated dendritic cells induce a type 2 helper T lymphocyte response through the OX40 ligand

BACKGROUND

Trichosanthin (TCS) induces a type 2 helper T lymphocyte (T(H)2) immune response that leads to the production of TCS-specific immunoglobulin (Ig) E and a subsequent allergic reaction in vivo. However, events immediately following treatment with TCS are poorly understood.

OBJECTIVE

We aimed to investigate whether dendritic cells (DCs) are the initial mediators of T(H)2 cell polarization induced by TCS and to investigate potential causative mechanisms

METHODS

DCs were cultured from purified human peripheral monocytes in the presence of granulocyte-macrophage colony-stimulating factor and interleukin (IL) 4. Flow cytometry was used to analyze cell surface antigen, intracellular cytokines, DC endocytic capacity, and apoptosis. The transcriptional profile for 120 genes in DCs was detected using oligonucleotide microarray analysis.

RESULTS

TCS exerted a cytotoxic effect on DCs in a concentration-dependent manner. Although TCS alone did not induce full maturation of DC, it did so in the presence of tumor necrosis factor alpha and IL-1beta in vitro. TCS-stimulated DCs induced a decreased ratio of T(H)1/T(H)2 cells derived from naïve T cells and showed selective expression of OX40 ligand (OX40L) at both mRNA and protein levels. This induction was partially blocked by anti-OX40L antibody.

CONCLUSION

Our results imply that TCS-stimulated DCs polarize the development of T(H)2 cells partially by means of the OX40L signal. Modulation of these DC will favor the alleviation of TCS-induced allergy.

Aggressive angiomyxoma of the vulva: intra-operative pathological diagnosis is useful in deciding the scope of surgery and reducing recurrence

Aggressive angiomyxoma (AA) is a rare, slow-growing myxoid neoplasm of the pelvi-perineum. Because of its rarity, it is often initially misdiagnosed, frequently as a gynaecological malignancy. Surgical resection is the main treatment modality of AA, but, local recurrence rates are high. In order to reduce recurrence, the scope of surgical resection should be as broad as possible. Intra-operative pathological diagnosis is useful in deciding the scope of surgery, and wide excision may reduce recurrence.

Adjuvant transcatheter arterial chemoembolization for intrahepatic cholangiocarcinoma after curative surgery: retrospective control study

BACKGROUND

Effects of adjuvant transcatheter arterial chemoembolization (TACE) for intrahepatic cholangiocarcinoma (ICC) radical surgery have never been evaluated.

METHODS

A retrospective analysis was conducted on 125 ICC patients who had undergone operations with curative intent in Shanghai Eastern Hepatobiliary Surgery Hospital from July 2002 to December 2003. Of these patients, 53 underwent adjuvant TACE (TACE group) and 72 did not (non-TACE group). Adjuvant TACE was performed one time 1.5-2.0 months after the operation.

RESULTS

Follow-up was performed at a median of 18 months (range 3-96 months). There was no significant recurrence-free survival (RFS) difference between the TACE and non-TACE groups (P = 0.659). The 1-, 3-, and 5-year overall survival (OS) rates were 69.8, 37.7, and 28.3%, respectively, for the TACE group and 54.2, 25.0, and 20.8%, respectively, for the non-TACE group (P = 0.045). Among 54 patients with a recurrence time of ≤ 3 months, the OS rate of the TACE group was better than that of the non-TACE group (P < 0.001). For 59 patients with a recurrence time later than the median RFS, no significant RFS difference was found between the TACE and non-TACE groups (P = 0.681). These results indicate that TACE could not delay recurrence but could prolong the OS of patients with early recurrence.

CONCLUSIONS

Adjuvant TACE after radical surgery was associated with better survival among the ICC patients with early recurrence.

New red flower germplasm lines of cotton selected from hybrid ofGossypium hirsutum XG. bickii

By means of dropping GA(3)(50 ppm) and NAA (40 ppm) on the hybrid boll-embryo culturein vitro, one F(1) plant ofG. hirsutum x G. bickii was obtained; when F(1) branches were grafted on upland cotton and then back-crossed with upland cotton under short-day and cooler-night condition, some BC(1) seeds could be harvested. The characteristic segregation was very violent in early generation. Through 3 times of back-crossing and selecting, ten stable hybrid lines with the character of both male parent (viz. red petal-purple spot and strong fibre) and female parent (plant type, earliness, white fibre, lint length, etc.) were established. These lines were assigned as HB red flower lines (HBRL). Transference of character ofG. bickii to upland cotton was proved to be successful for the first time. These new germplasms may play an important role in both the genetic research and new cotton variety breeding.

Eomesodermin, HAND1, and CSH1 proteins are induced by cellular stress in a stress-activated protein kinase-dependent manner

Eomesodermin (Eomes) is a transcription factor essential for trophoblast development. Stress stimuli activate stress-activated protein kinase (MAPK8/9) and modulate transcription factors in trophoblast stem cells (TSC). In this study, we test the hypothesis that stress-induced Eomes upregulation and downstream trophoblast development are MAPK8/9-dependent. Immunocytochemical and immunoblot assays suggest that Eomes is induced by hyperosmolar stress in a dose- and time-dependent manner. Two MAPK8/9 inhibitors that work by different mechanisms, LJNKl1 and SP600125, block induction of Eomes protein by stress. During normal TSC differentiation, the transcription factor heart and neural crest derivatives expressed 1 (HAND1) is dependent on Eomes, and chorionic somatomammotropin hormone 1 (CSH1) expression is dependent on HAND1. Similar to Eomes, HAND1 and CSH1 induction by stress are MAPK8/9-dependent, and CSH1 is induced in nearly all stressed TSC. CSH1 induction normally requires downregulation of the transcription factor inhibitor of differentiation 2 (ID2) as well as HAND1 upregulation. It was shown previously that hyperosmolar stress induces AMP-activated protein kinase (PRKAA1/2)-dependent ID2 loss in a MAPK8/9-independent manner. Inhibition of PRKAA1/2 with compound C and LJNKl1, more than MAPK8/9 inhibitors alone, inhibits the induction of CSH1 by stress. Taken together these data suggest that stress-induced MAPK8/9 and PRKAA1/2 regulate transcription factors Eomes/HAND1 and ID2, respectively. Together this network mediates induction of CSH1 by stress. Therefore, stress triggers a proportional increase in a normal early TSC differentiation event that could be adaptive in inducing CSH1. But the flexibility of TSC to undergo stress-induced differentiation could lead to pathophysiological consequences if stress endured and TSC differentiation became unbalanced.

Entangling different degrees of freedom by quadrature squeezing cylindrically polarized modes

Quantum systems such as, for example, photons, atoms, or Bose-Einstein condensates, prepared in complex states where entanglement between distinct degrees of freedom is present, may display several intriguing features. In this Letter we introduce the concept of such complex quantum states for intense beams of light by exploiting the properties of cylindrically polarized modes. We show that already in a classical picture the spatial and polarization field variables of these modes cannot be factorized. Theoretically it is proven that by quadrature squeezing cylindrically polarized modes one generates entanglement between these two different degrees of freedom. Experimentally we demonstrate amplitude squeezing of an azimuthally polarized mode by exploiting the nonlinear Kerr effect in a specially tailored photonic crystal fiber. These results display that such novel continuous-variable entangled systems can, in principle, be realized.

Abstract P5-05-07: The Loss of EcSOD Expression in Mammary Epithelial Cells Is Associated with Aberrant DNA Methylation When Mammary Tissue Organization Is Disrupted

Loss of tissue organization is one of the earliest manifestations of tumorigenic progression in breast cancer. It is well known that during structural and functional differentiation, mammary epithelial cells form polarized and organized structure called acini, which can be recapitulated in 3D culture system. Interestingly, we have recently found that gene expression of the extracellular superoxide dismutase (EcSOD) is differentially regulated in normal mammary epithelial cells (HMEC), in the 2D culture compared to the 3D culture system. We have previously shown that overexpression of EcSOD in EcSOD-null breast cancer cells resulted in inhibition of growth and invasion. Since heightened oxidative stress has been widely implicated in the etiology of human cancers and EcSOD is the predominant enzyme that modulates extracellular oxidative stress, understanding gene regulation of EcSOD is important in developing pharmalogical interventions for breast cancer. The expression of EcSOD in mammary epithelial cells was not recognized until recently. In fact, EcSOD mRNA and protein expression were not detectable in commercially available normal mammary epithelial cells which were cultured in 2Dcondition. However, our immuno-histological studies revealed a definitive positive staining for EcSOD in normal breast tissues specifically in mammary epithelium of the lobule and duct. Based on these observations, we hypothesized that EcSOD gene expression is lost when mammary tissue organization is disrupted. Therefore, we examined whether culturing HMEC in a 3D context, in the presence of extracellular matrix signaling and with the proper tissue organization, will reactivate EcSOD gene expression. Indeed, EcSOD gene expression was activated in HMEC after 4 days of 3D culture. We have further shown that the 3D cultured HMEC formed organized and polarized acinar structures by using immuno-fluorescence microscopy. Intriguingly, the expression of EcSOD dramatically decreased in a time dependent manner after passing the 10-day acini back into the 2D culture. Moreover, we observed a marked reduction of EcSOD immunoreactivity in ductal hyperplasia and ductal carcinoma in situ (DCIS) compared to normal mammary tissues. In addition, more than 87% of clinical mammary adenocarcinoma samples showed decreased EcSOD mRNA expression levels compared to their normal counterparts. We have further shown that EcSOD mRNA expression was strongly induced in 2D cultured HMEC after treatment with a DNA methyl transferase inhibitor and to a lesser extend with a histone deacetylase inhibitor. Furthermore, the diminished expression of EcSOD in 2D cultured HMEC is tightly associated with CpG hypermethylation of the EcSOD promoter. These results suggest that epigenetic mechanisms play an important role in regulating EcSOD gene expression and the loss of EcSOD expression in mammary adenocarcinomas could be due to aberrant CpG methylation of the EcSOD promoter. Taken together, our study implies that mammary tissue organization is required for EcSOD expression and that restoring EcSOD expression in mammary adenocarcinomas could be an effective strategy for breast cancer treatment.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-05-07.

Changes in ensemble activity of hippocampus CA1 neurons induced by chronic morphine administration in freely behaving mice

The hippocampus plays an important role in the formation of new memories and spatial navigation. Recently, growing evidence supports the view that it is also involved in addiction to opiates and other drugs. Theoretical and experimental studies suggest that hippocampal neural-network oscillations at specific frequencies and unit firing patterns reflect information of learning and memory encoding. Here, using multichannel recordings from the hippocampal CA1 area in behaving mice, we investigated the phase correlations between the theta (4-10 Hz) and gamma (40-100 Hz) oscillations, and the timing of spikes modulated by these oscillations. Local field potentials and single unit recordings in the CA1 area of mice receiving chronic morphine treatment revealed that the power of the theta rhythm was strongly increased; at the same time, the theta frequency during different behavioral states shifted markedly, and the characteristic coupling of theta and gamma oscillations was altered. Surprisingly, though the gamma oscillation frequency changed, the power of gamma lacking theta did not. Moreover, the timing of pyramidal cell spikes relative to the theta rhythm and the timing of interneuron spikes relative to the gamma rhythm changed during chronic morphine administration. Furthermore, these responses were impaired by a selective D1/D5 receptor antagonist intra-hippocampus injection. These results indicate that chronic morphine administration induced the changes of ensemble activity in the CA1 area, and these changes were dependent on local dopamine receptor activation.

Cellular stress causes reversible, PRKAA1/2-, and proteasome-dependent ID2 protein loss in trophoblast stem cells

Stress reduces fertility, but the mechanisms mediating this are not understood. For a successful pregnancy, placental trophoblast stem cells (TSCs) in the implanting embryo proliferate and then a subpopulation differentiates to produce hormones. Normally, differentiation occurs when inhibitor of differentiation 2 (ID2) protein is lost in human and mouse placental stem cells. We hypothesize that stress enzyme-dependent differentiation occurs in association with insufficient TSC accumulation. We studied a well-defined model where TSC differentiation requires ID2 loss. The loss of ID2 derepresses the promoter of chorionic somatomammotropin hormone 1 (CSH1), the first hormone after implantation. Csh1 mRNA is known to be induced in stressed TSCs. In this study, we demonstrate that AMP-activated protein kinase (PRKAA1/2, aka AMPK) mediates the stress-induced proteasome-dependent loss of ID2 at high stress levels. At very low stress levels, PRKAA1/2 mediates metabolic adaptation exemplified by the inactivation of acetyl coA carboxylase by phosphorylation without ID2 loss. At the highest stress levels, irreversible TSC differentiation as defined by ID2 loss and slower cell accumulation occurs. However, lower stress levels lead to reversible differentiation accompanied by metabolic adaptation. These data support the hypothesis that PRKAA1/2 mediates preparation for differentiation that is induced by stress at levels where a significant decrease in cell accumulation occurs. This supports the interpretation that enzyme-mediated increases in differentiation may compensate when insufficient numbers of stem cells accumulate.