Platelets govern pre-metastatic tumor communication to bone.

Although the survival rate for early detected cancers is high, once a cancer metastasizes to bone, it is incurable. Interestingly, patients without visible metastases display abnormal bone formation and resorption, suggesting a link between primary cancers and the bone microenvironment prior to metastasis, and this link likely facilitates preparation of the pre-metastatic niche. We hypothesized that communication with the primary tumor would result in bone remodeling alterations, and that platelets could facilitate this communication. By using three tumor models, we demonstrate that primary tumor growth stimulates bone formation measured by microcomputed tomography. Further, platelet depletion prevented tumor-induced bone formation, highlighting the importance of platelets in the communication between tumors and the bone microenvironment. Finally, we determine that platelets sequester a variety of tumor-derived proteins, TGF-ß1 and MMP-1 in particular, which regulate bone formation. Thus, our data reveal that platelets function as mediators of tumor-bone communication prior to metastasis.

Novel aspects of Kindlin-3 function in humans based on a new case of leukocyte adhesion deficiency III.

BACKGROUND: Kindlin-3 is a novel integrin activator in hematopoietic cells, and its deficiency leads to immune problems and severe bleeding, known as leukocyte adhesion deficiency III (LAD-III). Our current understanding of Kindlin-3 function primarily relies on analysis of animal models or cell lines. OBJECTIVES: To understand the functions of Kindlin-3 in human primary blood cells. PATIENTS/METHODS: We analyzed primary and immortalized hematopoietic cells obtained from a new LAD-III patient with immune problems, bleeding, a history of anemia, and abnormally shaped red blood cells. RESULTS: The patient's white blood cells (WBCs) and platelets showed defects in agonist-induced integrin activation and botrocetin-induced platelet agglutination. Primary leukocytes from this patient exhibited abnormal activation of ß(1) integrin. Integrin activation defects were responsible for the observed deficiency in the botrocetin-induced platelet response. Analysis of patient genomic DNA revealed a novel mutation in the Kindlin3 gene. The mutation abolished Kindlin-3 expression in primary WBCs and platelets, owing to abnormal splicing. Kindlin-3 is expressed in red blood cells (RBCs), and its deficiency is proposed to lead to abnormally shaped RBCs. Immortalized patient WBCs expressed a truncated form of Kindlin-3 that was not sufficient to support integrin activation. Expression of Kindlin-3 cDNA in immortalized patient WBCs rescued integrin activation defects, whereas overexpression of the truncated form did not. CONCLUSIONS: Kindlin-3 deficiency impairs integrin function, including activation of ß(1) integrin. Abnormalities in glycoprotein Ib-IX function in Kindlin-3-deficient platelets are secondary to integrin defects. The region of Kindlin-3 encoded by exon 11 is crucial for its ability to activate integrins in humans.

Radial aplasia in CHARGE syndrome: a new association.

CHARGE syndrome affects up to 1 in 8500 births, and is most commonly due to de novo truncating mutations in the CHD7 gene. In addition to the 4 major (choanal atresia, coloboma, cranial nerve dysfunction and characteristic ear abnormalities) and 7 minor features (genital hypoplasia, developmental delay, cardiac anomalies, growth retardation, orofacial clefting, tracheo-oesophageal fistula and characteristic facies) proposed by Blake et al. [K.D. Blake, S.L.H. Davenport, B.D. Hall, M.A. Hefner, R.A. Pagon, M.S. Williams, A.E. Lin, J.M. Graham Jr., CHARGE association: an update and review for the primary pediatrician, Clin. Pediatr. (Phila) 37 (1998) 159-173.], many different features have been described in affected patients. Limb defects do not feature in the original designation of the condition, but occasional reports have noted tibial aplasia and other less severe limb anomalies. Presented here is the first case of radial aplasia in a patient with CHARGE syndrome due to a novel frameshift mutation of CHD7.

Involvement of hydrogen peroxide in the differentiation and apoptosis of preosteoclastic cells exposed to arsenite.

Long-term exposure to sodium arsenite (AsO(2)) promotes the development of various cancers. Paradoxically, arsenic also induces pro-myelomonocytic leukemia cell differentiation, and at higher concentrations, apoptosis. The present study investigated the effects of AsO(2) on preosteoclasts. When treated with 2.5-5microM AsO(2), RAW264.7 cells underwent osteoclast differentiation as evidenced by an increase in the number of multinucleate cells expressing tartrate resistant acid phosphatase (TRAP). The appearance of these phenotypic markers was preceded by a low level increase in extracellular production of H(2)O(2) and was prevented by the addition of catalase (4.5microg/ml), an enzyme that removes H(2)O(2). Only at high concentrations (10-25microM) of AsO(2) was a significant loss of cell viability and a high level increase in H(2)O(2) production (1.5microM) observed. Apoptosis was blocked by pretreatment with diphenylene iodonium chloride (2microM), a NAD(P)H-flavoprotein inhibitor, suggesting the involvement of NADPH-oxidase. The data show that AsO(2), dose-dependently, stimulates increasing amounts of H(2)O(2) production. Moreover, at concentrations found in tissues of individuals exposed to geochemical AsO(2), osteoclasts underwent an H(2)O(2)-dependent differentiation. Therefore, chronic exposure to low-level amounts of AsO(2) could result in increased bone resorption and contribute to bone related pathologies.

Facial appearance in glycogen storage disease type III.

Amylo-1,6-glucosidase deficiency (glycogen storage disease type III) is associated with hypoglycaemia, hepatomegaly, raised transaminases and in most cases skeletal myopathy and cardiomyopathy. The disorder has not been considered to cause dysmorphism. We report consistent facial features in seven patients with GSD type III consisting of midface hypoplasia with a depressed nasal bridge and a broad upturned nasal tip, indistinct philtral pillars, and bow-shaped lips with a thin vermillon border. Younger patients had in addition deepset eyes. Several children had clinical problems such as persistent otitis media or recurrent sinusitis. The underlying aetiology of these features is unknown but the similarity in all our patient suggests that there is a facial phenotype for this disorder.

Precocious puberty, endometriosis, skeletal anomalies and mild hearing loss: a new autosomal dominant syndrome?

Two sisters presented at 13 and 15 years-of-age respectively with a history of precocious puberty, short stature, endometriosis and mild mixed hearing loss. They had mild learning difficulties and a number of skeletal features in common. Some of these features were present in their father, suggesting a new autosomal dominant entity.

Hirschsprung disease, microcephaly, mental retardation, and characteristic facial features: delineation of a new syndrome and identification of a locus at chromosome 2q22-q23.

We have identified six children with a distinctive facial phenotype in association with mental retardation (MR), microcephaly, and short stature, four of whom presented with Hirschsprung (HSCR) disease in the neonatal period. HSCR was diagnosed in a further child at the age of 3 years after investigation for severe chronic constipation and another child, identified as sharing the same facial phenotype, had chronic constipation, but did not have HSCR. One of our patients has an interstitial deletion of chromosome 2, del(2)(q21q23). These children strongly resemble the patient reported by Lurie et al with HSCR and dysmorphic features associated with del(2)(q22q23). All patients have been isolated cases, suggesting a contiguous gene syndrome or a dominant single gene disorder involving a locus for HSCR located at 2q22-q23. Review of published reports suggests that there is significant phenotypic and genetic heterogeneity within the group of patients with HSCR, MR, and microcephaly. In particular, our patients appear to have a separate disorder from Goldberg-Shprintzen syndrome, for which autosomal recessive inheritance has been proposed because of sib recurrence and consanguinity in some families.

Choanal atresia and hypothelia following methimazole exposure in utero: a second report.

We report on a 3-year-old boy with bilateral choanal atresia, hypoplastic nipples, and developmental delay who had been exposed to carbimazole in utero because of maternal Graves disease. His combination of abnormalities and facial appearance strongly resembles that of a previously reported child exposed to methimazole (which is the active metabolite of carbimazole) in utero. We suggest that this represents a rare but distinct syndrome of methimazole teratogenicity, probably related to first-trimester exposure. Recognition of such teratogenic effects is clearly important for genetic counselling and for management of subsequent pregnancies.

A bicycle ergometer for high altitude investigations.

The basic Monark bicycle ergometer was machined into twelve pieces which allowed it to be transported in backpacks to high altitudes. The machining, reassembly and calibration of the adapted ergometer are discussed. To determine whether the functional characteristics of the bicycle ergometer had been affected by the modifications, 18 subjects randomly pedalled a standard bicycle ergometer or the modified model at workloads of 300, 600 and 900 kpm at 50 rpm for 6 minutes at each level, while their heart rates and oxygen uptake values were collected. Subsequent analysis revealed no significant differences between bicycles for either heart rate or oxygen uptake. This adapted ergometer proved to be very functional for carrying out high altitude investigations in which a controlled work load is required.

Weight and velocity influences on kinesthetic learning and transfer of learning.

80 Ss performed a horizontal adduction movement of the arm attempting to approximate a velocity of 6 or 10 ft/sec with or without a 2-lb. weight in the hand, and Ss were randomly divided into 4 equal subgroups based upon the possible velocity-weight combinations. Ss were blindfolded and received only verbal cues as to the direction of error. After 60 trials on the initial task, each group was divided into 4 subgroups, based upon the original velocity-weight combinations, and performed 60 transfer trials. The two groups approximating the faster velocity were significantly more accurate on the initial task while weight had no effect on accuracy. Negative transfer occurred from the faster movement to the slower, more difficult movement.