The WNT receptor ROR2 drives the interaction of multiple myeloma cells with the microenvironment through AKT activation.

Multiple myeloma is the second most frequent hematological cancer after lymphoma and remains an incurable disease. The pervasive support provided by the bone marrow microenvironment to myeloma cells is crucial for their survival. Here, an unbiased assessment of receptor tyrosine kinases overexpressed in myeloma identified ROR2, a receptor for the WNT noncanonical pathway, as highly expressed in myeloma cells. Its ligand, WNT5A is the most abundant growth factor in the bone marrow of myeloma patients. ROR2 mediates myeloma cells interactions with the surrounding bone marrow and its depletion resulted in detachment of myeloma cells from their niche in an in vivo model, triggering apoptosis and thus markedly delaying disease progression. Using in vitro and ex vivo 3D-culture systems, ROR2 was shown to exert a pivotal role in the adhesion of cancer cells to the microenvironment. Genomic studies revealed that the pathways mostly deregulated by ROR2 overexpression were PI3K/AKT and mTOR. Treatment of cells with specific PI3K inhibitors already used in the clinic reduced myeloma cell adhesion to the bone marrow. Together, our findings support the view that ROR2 and its downstream targets represent a novel therapeutic strategy for the large subgroup of MM patients whose cancer cells show ROR2 overexpression.

Cellfood™ improves respiratory metabolism of endothelial cells and inhibits hypoxia-induced reactive oxygen species (ros) generation.

Endothelial mitochondria, the major site of ATP generation, modulate the intracellular dynamics of reactive oxygen species (ROS), which, in turn, control endothelial function. Adequate oxygen (O(2)) supply is required by endothelial cells (EC). Both hypoxia and hyperoxia may favor the overproduction of ROS leading to oxidative stress, mitochondrial damage and endothelial dysfunction. We investigated the capability and mechanisms of Cellfood™ (CF), an antioxidant compound, to modulate O(2) availability and mitochondrial respiratory metabolism and to regulate ROS generated by hypoxia in EC in vitro. Human umbilical vein endothelial cells (HUVEC) and ECV-304 were evaluated for the O(2) consumption using a Clark's electrode. The O(2) consumption rate rose, during the first minutes after CF addition and was associated with increase in mitochondrial oxidative capacity and good cell viability. Similar behaviours were observed when EC were exposed to CF for up to 8 days. The O(2) consumption increased and was accompanied by both intracellular rise of ATP and maintainment of LDH concentration. Hypoxia-induced ROS generation was significantly inhibited by CF, through the up-regulated expression of MnSOD, an anti-oxidant responsible for mitochondrial function preservation. The EC hypoxic response is mediated by the hypoxia master regulator HIF-1alpha whose activation was attenuated by CF, in concomitance with MnSOD up-regulation. Our results suggest a role for CF in improoving respiratory metabolism and in activating anti-oxidant mechanisms in EC, thus preserving endothelial function.

Improved function of circulating angiogenic cells is evident in type 1 diabetic islet-transplanted patients.

Circulating angiogenic cells (CACs) are vascular-committed bone marrow-derived cells that are dysfunctional in type 1 diabetes (T1D). Here we studied whether restoration of normoglycemia following islet transplantation is associated with better CAC function. We carried out a cross-sectional study of 18 T1D patients, 14 insulin-independent islet-transplanted patients (ITA) and 14 healthy controls (C) evaluating in vivo and in vitro CACs viability and function. We found that the percentage of CACs in vivo did not differ among the three groups while the number of CAC colonies obtained from T1D, but not from ITA, was reduced compared to C (C = 7.3 ± 1.9, T1D = 0.9 ± 0.4 and ITA = 4.7 ± 1.9; p < 0.05 T1D vs. all). In vitro CAC migration/differentiation were similar, while in vivo an improved angiogenic ability of ITA compared to T1D was shown (capillary density: C = 93.5 ± 22.1, T1D = 19.2 ± 2.8 and ITA = 44.0 ± 10.5, p < 0.05 T1D vs. all). Increased apoptosis and lesser IL-8 secretion were evident in CACs obtained from T1D compared to C and ITA. in vitro addition of anti-hIL-8 reduced the number of colonies obtained from C. Finally, T1D, but not ITA, had a lower endothelial-dependent dilatation (EDD) compared with C. These data suggest that CAC function is altered in T1D and may be improved after islet transplantation.

Productive infection of HUVEC by HHV-8 is associated with changes compatible with angiogenic transformations.

Kaposi's Sarcoma (KS) is an angioproliferative disease associated with human herpesvirus 8 (HHV-8) infection. We have characterized the morphologic and phenotypic modifications of HUVEC in a model of productive HHV-8 infection. HHV-8 replication was associated with ultra-structural changes, flattened soma and a loss of marginal folds and intercellular contacts, and morphologic features, spindle cell conversion and cordon-like structures formation. Phenotypic changes observed on cordon-like structures included partial loss and redistribution of CD31/PECAM-1 and VE-cadherin, uPAR up-regulation and de novo expression of CD13/APN. Such changes demonstrate the induction, in HUVEC, of an angiogenic profile. Most of these findings are directly linked to HHV-8-encoded proteins expression, suggesting that HHV-8 itself may participate to the initial steps of the angiogenic transformation in KS.

Is lingual nerve protection necessary for lower third molar germectomy? A prospective study of 300 procedures.

Lingual nerve damage is one of the most common complications of lower third molar removal. However evaluation of the factor involved in these lesions is difficult since most previous series are heterogeneous. The purpose of this prospective randomized study was to ascertain the impact of lingual nerve protection in a homogeneous series including only patients undergoing third molar germectomy (i.e. removal of the developmental bud prior to anchoring of the roots in the jaw). Data from a total of 300 germectomy procedures were included in this study. All procedures were performed by the same experienced surgeon randomly with or without lingual nerve protection. No lingual nerve injury was observed after third molar germectomy regardless of whether or not lingual nerve protection was used. Lingual nerve protection is unnecessary for lower third molar germectomy.

[Description and classification of extra-oral implants]. / Description et classification des implants extra-oraux.

There is no universal extra-oral implant (EOI) that provides an answer to all clinical situations. We present briefly the two main categories of extra-oral implants currently available, endo-osseous implants and juxta-osseous implants, comparing the advantages and disadvantages of each. We also discuss the new developments currently under experimentation in extra-oral implantology.

Loss of heterozygosity on chromosome 11q22-23 in melanoma is associated with retention of the insertion polymorphism in the matrix metalloproteinase-1 promoter.

Matrix metalloproteinase-1 (MMP-1, collagenase-1), which degrades interstitial collagen, is expressed at high levels by some tumor cells and is thought to enhance their invasiveness and metastatic potential. We recently described a common single nucleotide insertion polymorphism (2G allele) at -1,607 bp in the promoter of the MMP-1 gene that creates a binding site for the ETS family of transcription factors, and that is associated with enhanced transcription of this gene and increased enzyme activity. Allelic loss at the MMP-1 locus on chromosome 11 occurs in many tumors including melanoma, an invasive and aggressive cancer. We hypothesized that although loss of either the 1G or 2G allele from 1G/2G heterozygotes is random, retention of the transcriptionally more active 2G allele would favor tumor invasion and metastasis. As a result, a higher proportion of metastases would contain the 2G genotype than the 1G genotype. We report here the development of quantitative methods for assessing allelic loss at the MMP-1 locus, and demonstrate that 83% of the metastatic melanomas with loss of heterozygosity at this locus retained the 2G allele. This supports the hypothesis that retention of the 2G allele favors tumor invasion and metastasis in melanoma.

Paternally derived de novo interstitial duplication of proximal 15q in a patient with developmental delay.

Interstitial duplications of proximal 15q containing the Prader-Willi syndrome/Angelman syndrome (PWS/AS) region have been found in patients with autism or atypical autism. In these cases with an abnormal phenotype, the duplications were maternally derived. Paternal origin of the duplication has been associated with a normal phenotype. We report on a patient who presented with nonspecific developmental delay and partial agenesis of the rostral corpus callosum. Fluorescence in situ hybridization (FISH) studies using probes specific for the PWS/AS region demonstrated a double signal on one chromosome 15, indicating the presence of an interstitial duplication of proximal 15q involving the PWS/ AS region in the patient. Parental chromosomes were normal with FISH studies. Methylation analysis at exon alpha of the SNRPN locus showed a maternal band at 4.2 kb and a paternal band of apparent double intensity at 0.9 kb, suggestive of one copy of the maternal allele and two copies of the paternal allele in the patient. Microsatellite analysis was informative at the GABRB3 locus in the family, which showed the inheritance of two different paternal alleles and a maternal allele in the patient consistent with the origin of this duplication from an unequal crossing over between the two chromosome 15 homologs in the father. This is the first report of an abnormal phenotype associated with a paternally derived duplication of proximal 15q shown to contain the PWS/AS region by molecular techniques.

Maternal disomy and Prader-Willi syndrome consistent with gamete complementation in a case of familial translocation (3;15) (p25;q11.2).

Maternal uniparental disomy (UPD) for chromosome 15 is responsible for an estimated 30% of cases of Prader-Willi syndrome (PWS). We report on an unusual case of maternal disomy 15 in PWS that is most consistent with adjacent-1 segregation of a paternal t(3;15)(p25;q11.2) with simultaneous maternal meiotic nondisjunction for chromosome 15. The patient (J.B.), a 17-year-old white male with PWS, was found to have 47 chromosomes with a supernumerary, paternal der(15) consisting of the short arm and the proximal long arm of chromosome 15, and distal chromosome arm 3p. The t(3;15) was present in the balanced state in the patient's father and a sister. Fluorescent in situ hybridization analysis demonstrated that the PWS critical region resided on the derivative chromosome 3 and that there was no deletion of the PWS region on the normal pair of 15s present in J.B. Methylation analysis at exon alpha of the small nuclear ribonucleoprotein-associated polypeptide N (SNRPN) gene showed a pattern characteristic of only the maternal chromosome 15 in J.B. Maternal disomy was confirmed by polymerase chain reaction analysis of microsatellite repeats at the gamma-aminobutyric acid receptor beta3 subunit (GABRB3) locus. A niece (B.B.) with 45 chromosomes and the derivative 3 but without the der(15) demonstrated a phenotype consistent with that reported for haploinsufficiency of distal 3 p. Uniparental disomy associated with unbalanced segregation of non-Robertsonian translocations has been reported previously but has not, to our knowledge, been observed in a case of PWS. Furthermore, our findings are best interpreted as true gamete complementation resulting in maternal UPD 15 and PWS.

Acquisition and enhanced expression of the metastatic phenotype following transfections of genomic mouse tumor DNA containing human SCLC gene sequences.

Previous primary and secondary co-transfections of genomic DNA from a metastatic human small cell lung cancer cell line into NIH/3T3 cells resulted in a murine fibrosarcoma cell line (Tx93B) that produced frequent spontaneous lung metastases in subcutaneously injected tumor-bearing nude mice. In order to transfer the acquired metastatic behavior to additional cell lines that could then be tested in syngeneic immunocompetent animals, DNA from Tx93B cells was transfected without additional neo gene into Balb/c embryo fibroblasts, which led to the isolation of a tertiary transfectant cell line (D3) of low spontaneous metastatic potential in normal Balb/c mice. Subsequent cell lines established serially from lung metastases in mice injected with D3, and metastatic descendants of D3 (all selected for the original neo marker in G-418), resulted in three generations of metastatically variant cell lines capable of causing pulmonary metastases in 11.1%, 54.6%, and 89.5%, respectively, of subcutaneously injected animals, and in 100% of normal mice injected intraperitoneally. There was no apparent ras-family oncogene participation in the metastatic behavior of either of the two DNA donor cell lines or in the metastatically variant tertiary transfectants. Gelatin zymography indicated that the secretion of gelatinolytic enzymes in vitro by the variant cell lines was inversely proportional to their metastatic capability. Human Alu repeat gene sequences detected in the metastatic variants suggested that co-transfected metastasis-associated genes present in the original human DNA donor cell may have contributed to acquisition of the metastatic phenotype by the tertiary transfectant cell lines. The increase in metastatic potential observed in successive generations of the D3-derived tumor cell lines, further suggested that selection for cells having increased metastatic capability had occurred during passage in vivo accounting for the phenotypic change. Because of their common origin and progressively metastatic nature these cell lines may prove useful in the identification of metastasis-associated genes accessible through the use of differential expression cloning strategies.

Release of prostaglandin F1alpha and F2alpha from superfused platelets: quantitative evaluation of the inhibitory effects of some aspirin-like drugs.

The release of PGF1alpha and PGF2alpha from superfused blood platelets was studied by the combined use of two radioimmunoassay systems with different specificities. PGF1alpha only accounted for approximately 30% of the total immunoreactivity. A substantially similar pattern of release was obtained with platelets of rat and human origin, although the latter released considerably lower amount of both compounds. Indomethacin, Femoprofen, Ditazole and Aspirin all inhibited PGF2alpha release from rat platelets in descending order of potency. Hydrocortisone was partically inactive. The release of PGF1alpha and PGF2alpha was inhibited to the same extent by both Indomethacin and Fenoprofen. Moreover, a quite similar inhibitory effect by the same drug on rat and human platelets was found in preliminary experiments. In agreement with a previous similar finding, Aspirin displayed a higher inhibitory activity than that reported in other tissues. The use of superfused platelets seems to provide a simple and reproducible model for studying pharmacologic influences upon PG formation.