Abstract. Human osteopontin (OPN) is a glycosylated phosphoprotein which is expressed in a variety of tissues in the body. In recent years, accumulating evidence has indicated that the aberrant expression of OPN is closely associated with tumourigensis, progression and most prominently with metastasis in several tumour types. In this review, we present the current knowledge on the expression profiles of OPN and its main splice variants in human cancers, as well as the potential implications in patient outcome. We also discuss its putative clinical application as a cancer biomarker and as a therapeutic target. IntroductionOsteopontin (OPN) is a bone associated, extracellular matrix glycosylated phosphoprotein which is produced by several cell types, including osteoblasts, osteoclasts, immune cells, endothelial cells, epithelial cells and extra-osseous cells (skin, kidney and lung) (1-3). Due to differences in post-translational modification (PTM) (phosphorylation, glycosylation, sulfation and proteolysis) from different cellular sources, OPN has a molecular weight ranging from 41 to 75 kDa, which may have a cell type-specific structure and function (4-7). OPN plays a major role in various normal physiological processes, including bone remodelling, immune-regulation, inflammation and vascularisation (8,9). In addition, OPN has also been shown to be involved in carcinogenesis with multi-functional activities (10)(11)(12).OPN is involved in a series of biological functions through interactions with different integrins and CD44. Therefore, OPN is classified as a member of the ʻsmall integrin-binding ligand N-linked glycoproteins' (SIBLINGs) together with other molecules, including bone sialoprotein (BSP), dentin matrix protein 1 (DMP1), dentin sialophosphoprotein (DSPP) and matrix extracellular phosphoglycoprotein (MEPE) (13). Two critical integrin binding sequences of OPN have been identified: arginine-glycine-aspartic acid (RGD) and serine-valine-valinetyrosine-glutamate-leucine-arginine (SVVYGLR). OPN interacts mainly with various αv (particularly αvβ1, αvβ3, αvβ5) integrin receptors via the classical RGD sequence, and interacts with α9β1, α4β1, α4β7 via SVVYGLR (14-16). In addition, it also interacts with the CD44 splice variants, CD44v3, CD44v6 and CD44v7, via the C-terminal fragment calcium binding site (17)(18)(19)(20). These properties of OPN induce the activation of signal transduction pathways, leading to cell proliferation, adhesion, invasion and migration, which have been demonstrated by both in vitro and in vivo models (21-23). The binding of OPN to integrins and CD44 initiates a downstream signalling cascade via the PI3K/AKT signalling pathway leading to NF-κB mediated cell proliferation and survival (24)(25)(26). In additon, through the Ras/Raf/MEK/ERK signalling pathway, an OPN-integrin complex and subsequent induction of AP-1-dependent gene expression, urokinase-type plasminogen activator (uPA) and matrix metalloproteinases (MMPs) confer a metastatic phenotype on some cancer cell types (27)(28)(29...

1These authors contributed equally to this study.Abbreviations used: CAL, CFTR-associated ligand; CFTR, cystic fibrosis transmembrane conductance regulator; CT, carboxyl-terminus; ER, endoplasmic reticulum; GST, glutathione-S-transferase; HA, hemagglutinin; His, hexahistidinetagged; mGluR, metabotropic glutamate receptor; NHERF-2, Na + /H + exchanger regulatory factor-2; PDZ, PSD95/Discslarge/ZO1homology; SDS-PAGE, sodium dodecyl sulfatepolyacrylamide gel electrophoresis; siRNA, small interfering RNA. AbstractIn this study, we investigated the association of metabotropic glutamate receptor subtype-5a (mGluR5a) with cystic fibrosis transmembrane conductance regulator-associated ligand (CAL). Using glutathione-S-transferase pull-down techniques, we found that mGluR5a directly interacted with CAL, with the C-terminus of the receptor binding to the PSD95/Discslarge/ ZO-1 homology domain of CAL. The last four amino acids (S-S-S-L) of the C-terminus of the receptor were essential determinants for the interaction. Co-immunoprecipitation experiments and immunofluorescence assays revealed that full-length mGluR5a also associated with intact CAL in vivo, an observation consistent with the results from studies on fragment interactions in vitro. Functionally, upon co-expression with mGluR5a, CAL profoundly inhibited the ubiquitination of mGluR5a and enhanced receptor expression at the protein level but not at the mRNA level. These findings reveal that mGluR5a protein expression is physiologically regulated via its interaction with CAL. These results also suggest a molecular mechanism by which mGluR5a protein expression may be regulated at the post-translational level by the CAL protein, possibly by blocking ubiquitination-dependent receptor degradation.

Background: This study aimed to assess the different types of port-wine stain (PWS) skin lesions quantitatively using high-frequency ultrasound (US) and shear wave elastography (SWE) before and after treatment, and investigate the feasibility and application value of high-frequency US and SWE in PWSs.Methods: A total of 195 PWS patients with 238 skin lesions before treatment and 72 follow-up PWS patients with 90 skin lesions were assessed using high-frequency US and SWE. The skin lesions were divided into four groups: pink-type, purple-type, thickened-type, and nodular-type PWSs. Gray-scale US was used to observe normal skin, observe the skin changes of lesions, and assess the skin thickness. The thickened skin was calculated. Power Doppler (PD) signal grades were used to assess the skin blood signals. SW velocity (in m/s) and Young's elastic modulus (in kPa) were used to assess the stiffness of normal skin and skin lesions.The heightened SWE was also calculated. Results:The dermis hypoechogenicity, thickness of thickened skin, and skin PD signal grades were significantly higher in all PWS-type groups compared with the normal-skin group (all P<0.05). The thickened skin and skin PD signal grades in the nodular-type and thickened-type group were significantly thicker and higher than those in the pink-type and purple-type group (all P<0.05). The PD signal grades in the purple-type was significantly higher than that in the pink-type group (P<0.05). All SWE values of PWS lesions were significantly higher in the transverse section than those in the longitudinal section (all P<0.05). The differences in heightened E mean , E min , C mean , and C min between each PWS group and the normal-skin group were not significant. The heightened E max and C max in the nodular-type PWS group was significantly higher than those in the normal-skin group and pinktype, and purple-type PWS groups (all P<0.05). The heightened E max and C max were significantly higher in the thickened-type PWS group than those in the normal-skin group (all P<0.05). In the evaluation of therapeutic effects, the ratio of dermis hypoechogenicity in pink-type lesions significantly decreased, and thickened skins in all groups were significantly thinned (all P<0.05). The differences of PD signal grades, heightened E max , and C max in all groups between pre-treatment and post-treatment showed no significance.Conclusions: High-frequency US and SWE show feasibility and application values assessing PWS skin lesions. Their features include dermis hypoechogenicity, thicker skin, higher PD signal grades, higher E max , and higher C max . Thicker skin is thus the best feature for assessing therapeutic effect.

BACKGROUND: TACC2 is a member of the transforming acidic coiled-coil-containing protein family and is associated with the centrosome-spindle apparatus during cell cycling. In vivo, the TACC2 gene is expressed in various splice forms predominantly in postmitotic tissues, including heart, muscle, kidney, and brain. Recent work has shown that members of this family, including TACC2, may be involved in the progression of certain solid tumours. The aim of the current study was to identify the role of TACC2 in breast cancer and to establish if a prognostic relevance exists.MATERIALS AND METHODS: Fresh frozen primary human breast cancer tissues (n = 120) and non-neoplastic mammary tissues (n = 32) were used. The distribution and location of TACC2 was assessed using immunohistochemical staining (IHC) and imaging analysis tools. The transcript levels of TACC2 were determined using quantitative real time-PCR. The results were analyzed against the clinical, pathological and follow-up (10 years) data. Statistical analysis was by Mann-Whitney U test and Kaplan-Meier method. Shown are median transcript level.RESULTS: TACC2 protein staining was seen in both normal epithelial cells and cancer cells in mammary tissues. Increased staining of TACC2 was seen in most of the breast tumours examined when compared with normal breast tissues. Quantitative analysis of the TACC2 transcript also revealed a higher level expression in tumours compared with normal tissues (p=0.027, tumours vs normal). TACC2 expression was significantly increased in higher grade tumours compared to those in lower grade tumours (grade-3 vs grade-1, p=0.046). Using the Nottingham Prognostic Index (NPI), TACC2 transcript was significantly higher in tumours from patients with a moderate prognosis than from those with a good prognosis (p = 0.019). The expression in samples from patients with poor clinical outcome (with metastasis, recurrence and breast cancer related death) was significantly higher than that from patients who remained disease free (median (IQR) 33.8 (3.0-110.2) copies vs 6 (1.6-28.9) copies, p=0.038). This was reflected by the shorter disease-free survival for patients with high TACC2 (107 (91-122.8, 95% CI) months compared with 137 (125-150.6) months for patients with low TACC2 transcripts (p=0.019).CONCLUSION: This study shows that increased expression of TACC2 correlates with poor prognosis in patients with breast cancer. This suggests that TACC2 mediates an oncogenic effect on breast cancer cells. The findings also suggest that TACC2 may be a potential therapeutic target. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3159.

The purpose of this study was to investigate the performance of high-frequency ultrasound (HFUS) and shear wave elastography (SWE) in the quantitative evaluation of therapeutic responses of keloids. 43 patients with 76 keloids were recruited into this study. In keloids and symmetrical sites, the skin thickness was measured using HFUS and skin stiffness expressed as elastic moduli (Young’s modulus and shear wave velocity) was measured using SWE. The coefficient of variation values were calculated by using difference values of skin elastic moduli and skin thickness. A significant increase of both skin stiffness and thickness appeared in pre-treated keloids compared with post-treated keloids (P < 0.001) and normal controls (P < 0.001), respectively. Stiffness in post-treated keloids and normal skins was significantly different (P < 0.001), while the difference in thickness measurements showed no significance (P = 0.56, >0.05). The coefficient of variation of Young’s modulus was the highest when compared between (i) pre-treated keloids and theirs site-matched areas; (ii) pre-treated and post-treated keloids. SWE, which showed greater ability in determining the extent of keloids recovery, may provide an ideal tool to assess the stiffness of keloids and theirs therapeutic response.