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Supplementary Figure 1 from Caveolin-1 Reduces Osteosarcoma Metastases by Inhibiting c-Src Activity and Met Signaling

Caveolin-1 (Cav-1) is highly expressed in normal osteoblasts. This article reports that Cav-1 down-regulation is part of osteoblast transformation and osteosarcoma progression and validates its role as oncosuppressor in human osteosarcoma. A survey of 6-year follow-up indicates a better overall survival for osteosarcoma expressing a level of Cav-1 similar to osteoblasts. However, the majority of primary osteosarcoma shows significantly lower levels of Cav-1 than normal osteoblasts. Accordingly, Met-induced osteoblast transformation is associated with Cav-1 down-regulation. In vitro, osteosarcoma cell lines forced to overexpress Cav-1 show reduced malignancy with inhibited anchorage-independent growth, migration, and invasion. In vivo, Cav-1 overexpression abrogates the metastatic ability of osteosarcoma cells. c-Src and c-Met tyrosine kinases, which are activated in osteosarcoma, colocalize with Cav-1 and are inhibited on Cav-1 overexpression. Thus, Cav-1 behaves as an oncosuppressor in osteosarcoma. Altogether, data suggest that Cav-1 down-modulation might function as a permissive mechanism, which, by unleashing c-Src and Met signaling, enables osteosarcoma cells to invade neighboring tissues. These data strengthen the rationale to target c-Src family kinases and/or Met receptor to improve the extremely poor prognosis of metastatic osteosarcoma. [Cancer Res 2007;67(16):7675–85]

Supplementary Figure 2 from Caveolin-1 Reduces Osteosarcoma Metastases by Inhibiting c-Src Activity and Met Signaling

Supplementary Table 1 from Caveolin-1 Reduces Osteosarcoma Metastases by Inhibiting c-Src Activity and Met Signaling

Ewing sarcoma (EWS), the second most common malignant bone tumor in children and adolescents, occurs abruptly without clear evidence of tumor history or progression. Previous association studies have identified some inherited variants associated with the risk of developing EWS but a common picture of the germline susceptibility to this tumor remains largely unclear. Here, we examine the association between thirty single nucleotide polymorphisms (SNPs) of the

The single-stranded synthetic oligonucleotide PS2.M is known to provide a basis for developing sensors since it tends to fold into structures called G-quadruplexes (G4) having characteristic topology and orientation with probabilities that depend on the chemical environment. The presence and concentration of cation species are among the key factors that determine the outcome of such a process. PS2.M and other aptamers have been used in several applications in conjunction with various probes, such as hemin, at the cost of increased technical complexity and applicability limitations. We instead validated the application limits of Circular Dichroic spectroscopy (CD) as only measurement method to assay PS2.M as $${\hbox {K}}^{+}$$ K + sensor in a variety of solutions having different chemical complexity. The tested solutions range from simple $$\hbox {NaCl}$$ NaCl and $$\hbox {KCl}$$ KCl solutions to chemically complex solutions like DMEM—Dulbecco’s Modified Eagle Medium—which is widely used in a biological laboratory. PS2.M was also evaluated in solutions of $${\hbox {KHCO}}_{3}$$ KHCO 3 and D-ribose (K:D-rib), an antioxidant potassium compound, to compare its response to the simple $$\hbox {KCl}$$ KCl solution case. Our findings show that, within specific concentration applicability ranges, CD spectra can estimate the $${\hbox {K}}^{+}$$ K + concentration in the examined water solutions even at high $${\hbox {Na}}{+}$$ Na + concentrations with respect to $${\hbox {K}}^{+}$$ K + and in the presence of antioxidant molecules.

The single-stranded synthetic oligonucleotide PS2.M is known to provide a basis for developing sensors since it tends to fold into structures called G-quadruplexes (G4) having characteristic topology and orientation with probabilities that depend on the chemical environment. The presence and concentration of cation species are among the key factors that determine the outcome of such a process. PS2.M and other aptamers have been used in several applications in conjunction with various probes, such as hemin, at the cost of increased technical complexity and applicability limitations. We instead validated the application limits of Circular Dichroic spectroscopy (CD) as only measurement method to assay PS2.M asThe online version supplementary material available at 10.1140/epjp/s13360-022-02581-2.

Physical exercise is deemed the most efficient way of counteracting the age-related decline of skeletal muscle. Here we report a transcriptional study by next-generation sequencing of vastus lateralis biopsies from elderly with a life-long high-level training practice (n = 9) and from age-matched sedentary subjects (n = 5). Unsupervised mixture distribution analysis was able to correctly categorize trained and untrained subjects, whereas it failed to discriminate between individuals who underwent a prevalent endurance (n = 5) or a prevalent resistance (n = 4) training, thus showing that the training mode was not relevant for sarcopenia prevention. KEGG analysis of transcripts showed that physical exercise affected a high number of metabolic and signaling pathways, in particular those related to energy handling and mitochondrial biogenesis, where AMPK and AKT-mTOR signaling pathways are both active and balance each other, concurring to the establishment of an insulin-sensitive phenotype and to the maintenance of a functional muscle mass. Other pathways affected by exercise training increased the efficiency of the proteostatic mechanisms, consolidated the cytoskeletal organization, lowered the inflammation level, and contrasted cellular senescence. This study on extraordinary individuals who trained at high level for at least thirty years suggests that aging processes and exercise training travel the same paths in the opposite direction.

// Marcella Martinelli 1 , Alessandro Parra 2, 3 , Luca Scapoli 1 , Paola De Sanctis 1 , Valentina Chiadini 2, 3 , Claudia Hattinger 3 , Piero Picci 3 , Cinzia Zucchini 1, * , Katia Scotlandi 2, 3, * 1 Department of Experimental Diagnostics and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy 2 CRS Development of Biomolecular Therapies, Oncology Laboratory, Rizzoli Orthopaedic Institute, Bologna, Italy 3 Experimental Oncology Laboratory, Rizzoli Orthopaedic Institute, Bologna, Italy * Both authors have shared senior authorship Correspondence to: Katia Scotlandi, email: katia.scotlandi@ior.it Keywords: CD99, Ewing sarcoma, polymorphisms, association analysis Received: July 11, 2016 Accepted: October 03, 2016 Published: October 25, 2016 ABSTRACT Ewing sarcoma (EWS), the second most common primary bone tumor in pediatric age, is known for its paucity of recurrent somatic abnormalities. Apart from the chimeric oncoprotein that derives from the fusion of EWS and FLI genes, recent genome-wide association studies have identified susceptibility variants near the EGR2 gene that regulate DNA binding of EWS-FLI . However, to induce transformation, EWS-FLI requires the presence of additional molecular events, including the expression of CD99, a cell surface molecule with critical relevance for the pathogenesis of EWS. High expression of CD99 is a common and distinctive feature of EWS cells, and it has largely been used for the differential diagnosis of the disease. The present study first links CD99 germline genetic variants to the susceptibility of EWS development and its progression. In particular, a panel of 25 single nucleotide polymorphisms has been genotyped in a case-control study. The CD9 9 rs311059 T variant was found to be significantly associated [ P value = 0.0029; OR het = 3.9 (95% CI 1.5-9.8) and OR hom = 5.3 (95% CI 1.2-23.7)] with EWS onset in patients less than 14 years old, while the CD99 rs312257-T was observed to be associated [ P value = 0.0265; OR het = 3.5 (95% CI 1.3-9.9)] with a reduced risk of relapse. Besides confirming the importance of CD99 , our findings indicate that polymorphic variations in this gene may affect either development or progression of EWS, leading to further understanding of this cancer and development of better diagnostics/prognostics for children and adolescents with this devastating disease.

In a previous study, the whole transcriptome of the vastus lateralis muscle from sedentary elderly and from age-matched athletes with an exceptional record of high-intensity, life-long exercise training was compared—the two groups representing the two extremes on a physical activity scale. Exercise training enabled the skeletal muscle to counteract age-related sarcopenia by inducing a wide range of adaptations, sustained by the expression of protein-coding genes involved in energy handling, proteostasis, cytoskeletal organization, inflammation control, and cellular senescence. Building on the previous study, we examined here the network of non-coding RNAs participating in the orchestration of gene expression and identified differentially expressed micro- and long-non-coding RNAs and some of their possible targets and roles. Unsupervised hierarchical clustering analyses of all non-coding RNAs were able to discriminate between sedentary and trained individuals, regardless of the exercise typology. Validated targets of differentially expressed miRNA were grouped by KEGG analysis, which pointed to functional areas involved in cell cycle, cytoskeletal control, longevity, and many signaling pathways, including AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR), which had been shown to be pivotal in the modulation of the effects of high-intensity, life-long exercise training. The analysis of differentially expressed long-non-coding RNAs identified transcriptional networks, involving lncRNAs, miRNAs and mRNAs, affecting processes in line with the beneficial role of exercise training.

Problem To compare placental protein 13 (PP13) levels in the serum of women with primary postpartum hemorrhage (PPH) with a control population. Methods A prospective cohort study was conducted between May 2014 and May 2016 and included 435 pregnant women at term (38 weeks gestation) without any known risk factor and with normal labor. Multiples of median (MoM) were used to evaluate differences of the PP13 values between cases and controls. PP13 concentrations were adjusted for maternal and neonatal weight. Multivariable analysis was used to detect independent contribution of predictors of PPH. Results Fifteen had a major PPH >1000 mLs and represented the cases of the study. They were matched with 399 controls. Twenty-one patients who had a minor PPH (500-1000 mLs) were excluded. The mean observed rank in the PPH group was higher than that of controls (28.5 vs 13.5, P-value=.01). PP13 MoM values adjusted for maternal weight were higher than expected being 1.44±0.45 in PPH cases and 1.00±0.59 in controls (P-value .008). This difference was still significant even after adjustment for neonatal weight that represented a confounding variable. Conclusion Higher PP13 levels are independently associated with major PPH >1000 mLs.

Maturity Onset Diabetes of the young (MODY) is an autosomal dominant disease that includes clinically heterogeneous forms of not autoimmune diabetes that are caused by mutations in different genes. To date at least thirteen subtypes of MODY have been described. Hepatocyte Nuclear Factor-1α (HNF-1α) gene mutations (MODY3) lead to a severe form of diabetes during adolescence, with glycosuria and progressive reduction of insulin secretion. The management of pregnancies in women with familial diseases could be difficult. We reported a case of a 36-year-old woman at the 5th week of a twin, bicorial, biamniotic pregnancy, diagnosed with diabetes at 18 years of age, with negative autoimmunity and diabetes family history. Genetic tests on woman and on her family showed father, sister, first daughter and one of the twins, carriers of c.812G>A HNF-1α mutation. This case of a twin pregnancy, with only one fetus inheriting the disease, allowed us to evaluate the genotype influence in a shared metabolic environment.

PURPOSE: To quantify the mRNA levels of MMP-3, MMP-9, VEGF and Survivin in peripheral blood and the serum levels of CA-125 and Ca19-9 in women with and without endometriosis and to investigate the performance of these markers to differentiate between deep and ovarian endometriosis. METHODS: A case control study enrolled a series of 60 patients. Twenty controls have been matched with 20 cases of ovarian and 20 cases of deep endometriosis. Univariable and multivariable performance of serum CA125 and CA19-9, mRNA for Survivin, MMP9, MMP3 and VEGF genes have been evaluated by means of ROC curves and logistic regression, respectively. RESULTS: No difference in markers' concentration was detected between ovarian and deep endometriosis. In comparison with controls, serum CA125 and CA19 yielded the better sensitivity followed by mRNA for Survivin gene (81.5, 51.9 and 7.5% at 10% false positive rate, respectively). Multivariable estimated odds of endometriosis yielded a sensitivity of 87% at the same false positive rate. CONCLUSIONS: A combination of serum and molecular markers could allow a better diagnosis of endometriosis.

Objective To investigate whether a significantly aberrant expression of circulating placental mRNA genes related with cardiogenesis can be detected at the second trimester of pregnancy. Methods The study was performed in two stages. First stage (development model group): match of 14 placental tissues at delivery of fetuses with congenital heart disease versus 20 controls. Second stage (validation model group): mRNA amplification of abnormal expressed genes in maternal blood samples from 26 women bearing a fetus with a congenital heart disease matched with 28 controls. Results We identified four functional categories of genes possibly involved in abnormal heart development: cardiac morphogenesis: tenascin, thioredoxin, salvador homolog 1 protein; extracellular matrix (ECM) and valvular tissue biosynthesis; placental-associated plasma protein, collagen, type I, alpha 2, fibulin-1, heparanase, procollagen-proline, 2-oxoglutarate 4-dioxygenase, alpha polypeptide II, Jumonji, AT rich interactive domain 1B RBP2-like; normal contractile activity: actinin, alpha 4, fascin homolog 1, actin-bundling protein; and congestive heart failure. Conclusion Altered placental genetic expression was found at term delivery in affected fetuses. The aberration was also confirmed in maternal blood at the second trimester of women bearing a fetus with congenital heart disease. Sensitivity for the most aberrant genes ranged between 42% and 95% at a false positive rate (FPR) of 10%. Copyright © 2010 John Wiley & Sons, Ltd.

Objectives To determine the gene expression profile in chorionic villous samples (CVSs) of women destined to develop pre-eclampsia (PE). Method Case-control study encompassing five women destined to develop PE [cases matched for gestational age with 30 controls]. We quantified mRNA expression on tissue samples from CVS of normal and PE patients. We then assessed mRNA expressions of cathepsin (CTSD), angiopoietin 2 (ANGPT2), interleukin 8, chemokine (C-X-C motif) ligand 10, neurokinin B (NKB), matrix metallopeptidase 9, major histocompatibility complex, class I, C (HLA-C)and human leukocyte antigen-G (HLA-G). Data were analyzed by nonparametric rank analysis. Results For all the mRNA species considered in this study, except CTSD and ANGPT2, all the mean observed ranks in the PE group were significantly altered compared with the rank expectation among controls. mRNA for NKB and HLA-C were the markers with the highest degree of aberration in PE, compared with those in controls. Conclusion Our study has directly showed that gene expressions relating to trophoblastic cell invasion or utero-placental hemodynamic adaptation are altered in the first trimester trophoblasts that go on to develop PE later. These results posit the use of residual CVS as a possible screening method for PE. Copyright © 2011 John Wiley & Sons, Ltd.

Objective To evaluate the direct alterations in mRNA expression among chorionic villous samples from 11 weeks' pregnant women who would develop preeclampsia (PE) later in the pregnancy. Method Case-control study encompassing five women destined to develop PE [cases matched 1:5 for gestational age (GA) with 25 controls]. We quantified mRNA expression on tissue samples from chorionic villous sampling (CVS) of normal and PE patients. We then assessed mRNA expressions of vascular endothelial growth factor (VEGFA), VEGFA receptor 1 (Flt-1), endoglin (Eng), placental growth factor (PlGF), transforming growth factor-β1 (TGF-β1), heme oxygenase-1 (HO-1) and superoxide dismutase (SOD). Data were analyzed by nonparametric rank analysis. Results For all the mRNA species considered in this study, all the mean observed ranks in the PE group were significantly altered compared to the rank expectation among controls. mRNA for Eng and TGF-β1 were the markers with the highest degree of aberration in PE, in respect to controls. The results are consistent with those already reported for the corresponding circulating proteins. mRNA for HO-1 and SOD were instead associated with the lowest aberration. Conclusion It is assumed that the pathogenesis of PE is associated with pathophysiological alterations to trophoblasts in early gestation. Our study has directly proved that gene expressions relating to angiogenesis or oxidative stress are altered in the first trimester trophoblasts that go on to develop PE later. These results would put the basis for a possible screening method for PE by using residual CVS. Copyright © 2008 John Wiley & Sons, Ltd.

Aim: In view of accumulating evidence supporting a pivotal role of the Rho/ROCK pathway in cancer, we investigated Rho-kinase polymorphisms as potential susceptibility factors in colorectal cancer (CRC) in a representative sample of the Italian population. Methods: DNA obtained from the peripheral blood samples of 137 CRC patients and 141 healthy controls was genotyped for four ROCK1 (rs35996865; rs73963110; rs2127958; rs288980) and five ROCK2 (rs12692437; rs7563468; rs35768389; rs17463896; rs16857265) selected single nucleotide polymorphisms. Results: None of the allelic variants of the nine selected markers was associated with the occurrence of CRC or with the development of regional lymph node metastasis. By contrast, the ROCK1 rs35996865 G variant allele was significantly more frequent in male patients (p = 0.028) than in the control group. Conclusion: This finding is, at present, the first that points to a possible gender-related modulation by the ROCK1 gene in CRC susceptibility.

BJECTIVES: To determine the gene expression profile in chorionic villous samples (CVSs) of women destined to develop pre-eclampsia (PE). METHOD: Case-control study encompassing five women destined to develop PE [cases matched for gestational age with 30 controls]. We quantified mRNA expression on tissue samples from CVS of normal and PE patients. We then assessed mRNA expressions of cathepsin (CTSD), angiopoietin 2 (ANGPT2), interleukin 8, chemokine (C-X-C motif) ligand 10, neurokinin B (NKB), matrix metallopeptidase 9, major histocompatibility complex, class I, C (HLA-C)and human leukocyte antigen-G (HLA-G). Data were analyzed by nonparametric rank analysis. RESULTS: For all the mRNA species considered in this study, except CTSD and ANGPT2, all the mean observed ranks in the PE group were significantly altered compared with the rank expectation among controls. mRNA for NKB and HLA-C were the markers with the highest degree of aberration in PE, compared with those in controls. CONCLUSION: Our study has directly showed that gene expressions relating to trophoblastic cell invasion or utero-placental hemodynamic adaptation are altered in the first trimester trophoblasts that go on to develop PE later. These results posit the use of residual CVS as a possible screening method for PE.

Objective The purpose of this study was to determine whether the combined distribution of a panel of cellular messenger RNA markers can detect preeclampsia long before onset. Study Design We compared blood at 10-14 weeks from 11 women who ultimately experienced preeclampsia with 88 matched control subjects. After multiples of the median conversion of all the markers, logistic regression was used to calculate the risk of the development of preeclampsia. Results Higher multiples of the median values than expected were found for endoglin, fms-related tyrosine kinase 1, and transforming growth factor–β1. Lower multiples of the median values were found for placental growth factor and placental protein 13. Endoglin fms-related tyrosine kinase 1 and transforming growth factor–β1 had the best discriminant power. Messenger RNA species provided independent contributions to the prediction of preeclampsia. In fact, 11 women with preeclampsia scored a median risk of 50% of experiencing preeclampsia. Control subjects scored a median risk of preeclampsia of 0.18%. The detection rate at a 5% false positive rate was 72.3%. Conclusion The messenger RNA dosage in maternal blood would be a useful method for the calculation of the risk of the development of preeclampsia.

Background/Aims: Endometriosis is an invasive disease. Its diagnosis depends on laparoscopy, which is traumatic and associated with potential complications. The aim of this study was to develop a rapid, reliable, and less invasive diagnostic test for endometriosis. We hypothesized that genes related to cell invasion would be transcriptionally upregulated in endometriosis, and tested whether blood levels of their transcripts might be used as biomarkers of endometriosis.Methods:We used quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) to quantify the mRNA levels of vascular endothelial growth factor A (VEGFA), matrix metalloproteinase-3 (MMP-3), and MMP-9 in peripheral blood from 20 patients with mild/intermediate endometriosis, 20 patients with severe endometriosis and 20 endometriosis-free subjects. Results:Our results indicate that circulating mRNA for MMP-3 is significantly higher in patients with endometriosis than in control patients, regardless of the degree of severity. Conversely, the level of circulating mRNA for VEGFA and MMP-9 did not distinguish patients from controls. Conclusion: MMP-3 mRNA is a promising peripheral blood marker that discriminates between patients with endometriosis and healthy subjects. Our results support the possibility of finding genes suitable for diagnostic qRT-PCR for endometriosis in peripheral blood and should be explored further.

Metastasis is the most frequent cause of death among patients with osteosarcoma. We have previously demonstrated in independent experiments that the forced expression of L/B/K ALP and CD99 in U-2 OS osteosarcoma cell lines markedly reduces the metastatic ability of these cancer cells. This behavior makes these cell lines a useful model to assess the intersection of multiple and independent gene expression signatures concerning the biological problem of dissemination. With the aim to characterize a common transcriptional profile reflecting the essential features of metastatic behavior, we employed cDNA microarrays to compare the gene expression profiles of L/B/K ALP- and CD99-transfected osteosarcoma clones showing low metastatic ability with those of osteosarcoma cell lines showing contrasting behavior. Changes in gene expression were validated by real-time PCR and immunohistochemistry in independent samples. In our study we identified several differentially expressed genes (GADD45alpha, VCP, DHX9, survivin, alpha-catulin, ARPC1B) related to growth arrest and apoptosis. Most of these genes are functionally related with the nuclear factor (NF)-kappaB cell survival pathway that appeared to be inhibited in the less malignant osteosarcoma cells. Hence, we propose the inhibition of the NF-kappaB pathway as a rational strategy for effective management of human osteosarcoma.

Caveolin-1 (Cav-1) is highly expressed in normal osteoblasts. This article reports that Cav-1 down-regulation is part of osteoblast transformation and osteosarcoma progression and validates its role as oncosuppressor in human osteosarcoma. A survey of 6-year follow-up indicates a better overall survival for osteosarcoma expressing a level of Cav-1 similar to osteoblasts. However, the majority of primary osteosarcoma shows significantly lower levels of Cav-1 than normal osteoblasts. Accordingly, Met-induced osteoblast transformation is associated with Cav-1 down-regulation. In vitro, osteosarcoma cell lines forced to overexpress Cav-1 show reduced malignancy with inhibited anchorage-independent growth, migration, and invasion. In vivo, Cav-1 overexpression abrogates the metastatic ability of osteosarcoma cells. c-Src and c-Met tyrosine kinases, which are activated in osteosarcoma, colocalize with Cav-1 and are inhibited on Cav-1 overexpression. Thus, Cav-1 behaves as an oncosuppressor in osteosarcoma. Altogether, data suggest that Cav-1 down-modulation might function as a permissive mechanism, which, by unleashing c-Src and Met signaling, enables osteosarcoma cells to invade neighboring tissues. These data strengthen the rationale to target c-Src family kinases and/or Met receptor to improve the extremely poor prognosis of metastatic osteosarcoma. [Cancer Res 2007;67(16):7675–85]

The causative molecular pathways underlying the pathogenesis of colorectal cancer (CRC) need to be better characterized. The purpose of our study was to better understand the genetic mechanism of oncogenesis for human colorectal cancer and to identify new potential tumor markers of use in clinical practice. We used cDNA microarrays to compare gene expression profiles of colorectal biopsies from 25 CRC patients and 13 normal mucosa from adjacent non-cancerous tissues. Findings were validated by real-time PCR; in addition, western blotting and immunochemistry analysis were carried out as further confirmation of differential expression at a protein level. Comparing cancerous tissues with normal colonic mucosa we identified 584 known genes differentially expressed to a significant degree (p

Research has widely supported the efficacy of screening for colorectal cancer in reducing mortality. A blood-based assay potentially represents a more accessible early detection tool for the identification of solid tumor cells originating from a primary tumor site in the body. We demonstrate a relatively easy and highly reproducible technique for the detection of mRNA expression of genes as markers of malignancy in blood samples of patients with colon cancer. The present study aims to identify a set of specific mRNAs expressed in epithelial cells but not in blood cells, which may be useful as markers for early detection of circulating colon cancer cells by a simple, qualitative RT-PCR assay following semi-automated RNA extraction from peripheral blood samples. Our approach includes a systematic search for candidate markers using digital differential display, search on UniGene colon EST libraries and analysis of published data on colon cancer gene expression. A final list included the following genes: bone morphogenetic protein 4 (BMP4), cyclin D (CycD), family with sequence similarity 3, member D (FAM3D), gastrin (GAS), glycoprotein A33 transmembrane (GPA33), glutathione peroxidase 2 gastrointestinal (GPX2), galactoside-binding, soluble, 4 (galectin 4) (LGALS4), non-SMC, structural maintenance of chromosomes, element 1 protein (NSE1), tumor-associated calcium signal transducer 1 (TACSTD1), telomerase reverse transcriptase (hTERT), trefoil factor 3 intestinal (TFF3), transmembrane 4 superfamily member 3 (TM4SF3), UDP glycosyltransferase 1 family, polypeptide A9 (UGT1A9), villin 1 (VIL1), and the novel gene FLJ20127. The mRNA expression of these genes was evaluated in a pool of 16 samples from subjects diagnosed with colon cancer and from 16 normal-controls. We observed expression in 13 of the 15 investigated genes from the blood samples of the vast majority of patients considered, but also in a certain percentage of the controls (from 14.3 to 100%). This finding confirms that the extreme sensitivity of RT-PCR is able to detect minimal amounts of mRNA expressed in a non tissue-specific manner ('illegitimate transcription'). On the contrary, NSE1 and GAS mRNAs were not detected either in patient or in control blood samples; however, they were abundantly expressed in normal and cancerous colon mucosa, encouraging further search for useful markers able to detect epithelial cells in peripheral blood.

CD99 is a 32-kDa highly glycosylated transmembrane protein encoded by MIC2 gene which shares no homology with any known family of proteins except Xga and mouse CD99L2 proteins. Located in the pseudoautosomal region of chromosomes X and Y, MIC2 encodes two distinct products by alternative splicing of gene transcripts: a long form (32-kDa), corresponding to the full-length protein (CD99wt) and a short form harbouring a deletion in the intracytoplasmic domain (CD99 sh). CD99 is involved in multiple cellular events including cell adhesion, apoptosis, differentiation of T- cells and thymocytes, transendothelial migration of leukocytes, maintenance of cellular morphology and regulation of intracellular membrane protein trafficking either in physiology and in pathological conditions. In osteosarcoma, CD99 is expressed at low levels and functions as a tumor suppressor. The two alternative spliced isoforms are associated to distinct functional outcomes: CD99sh expression increases, whereas wtCD99 significantly inhibits migration, invasiveness and metastasis of osteosarcoma cells (Manara MC, 2006; Scotlandi K 2007). In this study, we specifically analyzed modulation of cell-cell contacts, reorganization of the actin cytoskeleton, and modulation of signalling pathways by comparing osteosarcoma cells characterized by different metastasis capabilities and CD99 expression, to identify molecular mechanisms responsible for metastasis. Our data indicate that expression of CD99wt induces recruitment of beta-catenin to adherens injunctions through N-cadherin up-regulation. In addition, forced expression of CD99wt inhibits the expression of several molecules crucial to remodeling the actin cytoskeleton, such as ACTR2 (also named ARP2), ARPC1A and ROCK II as well as ezrin, an ezrin/radixin/moesin (ERM) family member that has been clearly associated with tumor progression and metastatic spread either in experimental models and clinical samples of osteosarcoma. Functional studies by siRNA and/or specific inhibitors point to ROCKII as a crucial intracellular mediator regulating osteosarcoma metastasis capabilities. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4325. doi:1538-7445.AM2012-4325