The aim of this study was to facilitate and deepen the understanding of the associations of the microRNA-29 (miR-29) family with tumor progression and patients' prognosis of primary osteosarcoma. We examined expression levels of miR-29a, miR-29b, and miR-29c in tumor tissues and patients' sera of 80 cases of primary osteosarcomas by quantitative real-time reverse transcriptase-polymerase chain reaction. The correlations of their serum levels with clinicopathological characteristics and patient prognosis were also analyzed. The expression levels of miR-29a, miR-29b, and miR-29c in osteosarcoma tissues and patients' sera were all significantly higher than those in normal controls (all P < 0.05). The serum levels of miR-29a and miR-29b in the patients with higher tumor grade (both P = 0.01), positive metastasis (both P = 0.006), and positive recurrence (both P = 0.006) were both markedly higher than those with lower tumor grade, negative metastasis, and negative recurrence. According to the survival analysis of 80 osteosarcoma patients, cases in the miR-29a-high and miR-29b-high-expression groups both showed shorter overall survival (OS, both P < 0.001) and disease-free survival (DFS, both P < 0.001). Furthermore, the serum levels of miR-29a and miR-29b were both independent prognostic factors for OS and DFS of osteosarcoma patients. However, high miR-29c level was not related to any clinicopathological characteristics and patient prognosis of osteosarcomas (P > 0.05). The findings from the present study reveal that the miR-29 family may play crucial roles in the development and progression of human osteosarcoma. In particular, the serum levels of miR-29a and miR-29b may well estimate the prognosis of patients with this malignancy.

Little is known about the significance of the two types of glutamatergic neurons (those expressing vesicular glutamate transporter VGLUT1 or VGLUT2) in the control of jaw movements. We thus examined the origin and distribution of axon terminals with VGLUT1 or VGLUT2 immunoreactivity within the trigeminal motor nucleus (Vm) in the rat. The Vm was divided into the dorsolateral division (Vm.dl; jaw‐closing motoneuron pool) and the ventromedial division (Vm.vm; jaw‐opening motoneuron pool). VGLUT1‐immunopositive terminals were seen within the Vm.dl only, whereas VGLUT2‐immunopositive ones were distributed to both the Vm.dl and the Vm.vm. Transection of the motor root eliminated almost all VGLUT1‐immunopositive axons in the Vm.dl, with no changes of VGLUT2 immunoreactivity in the two divisions, indicating that the VGLUT1‐ and VGLUT2‐immunopositive axons came from primary afferents in the mesencephalic trigeminal nucleus and premotor neurons for the Vm, respectively. In situ hybridization histochemistry revealed that VGLUT2 neurons were much more numerous than VGLUT1 neurons in the regions corresponding to the reported premotoneuron pool for the Vm. The results of immunofluorescence labeling combined with anterograde tract tracing further indicated that premotor neurons with VGLUT2 in the trigeminal sensory nuclei, the supratrigeminal region, and the reticular region ventral to the Vm sent axon terminals contacting trigeminal motoneurons and that some of the VGLUT1‐expressing premotor neurons in the reticular region ventral to the Vm sent axon terminals to jaw‐closing motoneurons. The present results suggested that the roles played by glutamatergic neurons in controlling jaw movements might be different between VGLUT1‐ and VGLUT2‐expressing neurons. J. Comp. Neurol. 512:595–612, 2009. © 2008 Wiley‐Liss, Inc.

It has often been suggested that the trigemino- and spino-thalamic pathways are highly implicated in sensory-discriminative aspects of pain, whereas the trigemino- and spino-parabrachial pathways are strongly implicated in affective/emotional aspects of pain. On the other hand, the superficial laminae of the spinal dorsal horn, where many nociceptive neurons are distributed, have been reported to contain projection neurons innervating both the parabrachial nucleus (PBN) and thalamus by way of axon collaterals (Hylden et al., 1989). For the medullary dorsal horn (caudal subnucleus of spinal trigeminal nucleus: Vc), however, the existence of such neurons has not been reported. Thus, in the present study, we examined whether the Vc might contain projection neurons sending their axons to both the thalamus and PBN. Dual retrograde labeling with fluorescence dyes was attempted. In each rat, tetramethylrhodamine-dextran amine and Fluoro-gold were stereotaxically injected into the PBN and thalamic regions, respectively. The proportion of the dually labeled Vc cells in the total population of all labeled Vc cells was about 20%. More than 90% of the dually labeled neurons were distributed in lamina I (marginal zone), less than 10% of them were located in lamina II (substantia gelatinosa), and only a few (about 1%) were found in lamina III (magnocellular zone). The results indicate that some Vc neurons in the superficial laminae mediate nociceptive information directly to the PBN and thalamus by way of axon collaterals and that the vast majority of them project to the ipsilateral PBN and contralateral thalamus.