MicroRNA-107 is a novel tumor suppressor targeting POU3F2 in melanoma

BACKGROUND: Melanoma is one of the major types of skin cancer. The metastatic melanoma is among the most lethal forms of malignant skin tumors. We hereby aimed to characterize a novel microRNA (miR) in the metastatic melanoma model. METHODS: First, we evaluated the expression of miR-107 in melanoma cells and tumor tissues. The comparison between primary and metastatic cancer tissues was also accessed. Next, we examined the impact of miR-107 on melanoma cell proliferation, cell cycle, colony formation, apoptotic activity, migration and matrix invasion. A downstream target of miR-107 was also predicted and validated functionally in melanoma cells. RESULTS: Our findings showed miR-107 was significantly downregulated in melanoma. Its expression was lowest in metastatic form. Over-expression of miR-107 reduced melanoma cell proliferation, migration and invasion. POU3F2 was identified as the downstream target of miR-107. Over-expression of POU3F2 antagonized miR-107-mediated inhibitory effect on melanoma cells. CONCLUSION: Our study has reported miR-107 as a novel tumor suppressive factor in the metastatic melanoma model. It has provided new avenue to manage melanoma and improve the survival rate in the advanced stage.

AMutation Causes Nonsyndromic Hearing Loss in a Chinese X-linked Recessive Family / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The molecular genetic research showed the association between X-linked hearing loss and mutations in POU3F4. This research aimed to identify a POU3F4 mutation in a nonsyndromic X-linked recessive hearing loss family.</p><p><b>METHODS</b>A series of clinical evaluations including medical history, otologic examinations, family history, audiologic testing, and a high-resolution computed tomography scan were performed for each patient. Bidirectional sequencing was carried out for all polymerase chain reaction products of the samples. Moreover, 834 controls with normal hearing were also tested.</p><p><b>RESULTS</b>The pedigree showed X-linkage recessive inheritance pattern, and pathogenic mutation (c.499C>T) was identified in the proband and his family member, which led to a premature termination prior to the entire POU domains. This mutation co-segregated with hearing loss in this family. No mutation of POU3F4 gene was found in 834 controls.</p><p><b>CONCLUSIONS</b>A nonsense mutation is identified in a family displaying the pedigree consistent with X-linked recessive pattern in POU3F4 gene. In addition, we may provide molecular diagnosis and genetic counseling for this family.</p>

Localization of rDNA sites in holocentric chromosomes of three species of triatomines (Heteroptera, Triatominae)

Chromatin organization in the holocentric chromosomes of three triatomines species was cytologically studied by fluorescent in situ hybridization with a 45S rDNA probe of Drosophila melanogaster to localize ribosomal genes. In Triatoma tibiamaculata, metaphases I showed telomeric highlights in a single, larger bivalent. In T. protacta, hybridization was detected in one of the telomeres of an autosomal chromosome. In T. platensis, there were highlights in a single, smaller chromosome (X chromosome). The results obtained did not agree with the expected localization of rDNA genes in the sex chromosomes of triatomines, as demonstrated by silver impregnation, and suggest that the chromosome reorganization that occurred in this group during evolution may be a more important mechanism involved in rDNA distribution.

Detection of POU3F4 gene mutations in the Chinese pedigree with Y-linked hereditary hearing impairment / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To analyze the mutations of candidate POU3F4 gene in the Chinese pedigree with Y linked hereditary hearing impairment.</p><p><b>METHODS</b>Polymerase chain reaction (PCR) reactions were performed with five pairs of primer in the coding sequence of POU3F4 gene. PCR-single-strand conformation polymorphism (PCR-SSCP) was subsequently applied in the 43 individuals of DFNY1 family for screening the gene mutations.</p><p><b>RESULTS</b>The PCR amplification fragments showed well quality in the five pairs of primer and further analysis with PCR-SSCP showed no any polymorphism and mutations in the members.</p><p><b>CONCLUSIONS</b>The possibility of the deafness gene POU3F4, which locates on the translocation region on X and Y chromosome, contributed to the Y linked family deafness was successfully ruled out. It may imply that the causal gene of the DFNY1 family locate on the Y chromosome.</p>

The wings of Bombyx mori develop from larval discs exhibiting an early differentiated state: a preliminary report.

Lepidopteran insects present a complex organization of appendages which develop by various mechanisms. In the mulberry silkworm, Bombyx mori a pair of meso- and meta-thoracic discs located on either side in the larvae gives rise to the corresponding fore- and hind-wings of the adult. These discs do not experience massive cell rearrangements during metamorphosis and display the adult wing vein pattern. We have analysed wing development in B. mori by two approaches, viz., expression of patterning genes in larval wing discs, and regulatory capacities of larval discs following explantation or perturbation. Expression of Nubbin is seen all over the presumptive wing blade domains unlike in Drosophila, where it is confined to the hinge and the wing pouch. Excision of meso- and meta-thoracic discs during the larval stages resulted in emergence of adult moths lacking the corresponding wings without any loss of thoracic tissues suggesting independent origin of wing and thoracic primordia. The expression of wingless and distal-less along the dorsal/ventral margin in wing discs correlated well with their expression profile in adult Drosophila wings. Partially excised wing discs did not show in situ regeneration or duplication suggesting their early differentiation. The presence of adult wing vein patterns discernible in larval wing discs and the patterns of marker gene expression as well as the inability of these discs to regulate growth suggested that wing differentiation is achieved early in B. mori. The timings of morphogenetic events are different and the wing discs behave like presumptive wing buds opening out as wing blades in B. mori unlike evagination of only the pouch region as wing blades seen in Drosophila.