MicroRNA-320a inhibits breast cancer metastasis by targeting metadherin.

Dysregulated microRNAs play important pathological roles in carcinogenesis that are yet to be fully elucidated. This study was performed to investigate the biological functions of microRNA-320a (miR-320a) in breast cancer and the underlying mechanisms. Function analyses for cell proliferation, cell cycle, and cell invasion/migration, were conducted after miR-320a silencing and overexpression. The specific target genes of miR-320a were predicted by TargetScan algorithm and then determined by dual luciferase reporter assay and rescue experiment. The relationship between miR-320a and its target genes was explored in human breast cancer tissues. We found that miR-320a overexpression could inhibit breast cancer invasion and migration abilities in vitro, while miR-320a silencing could enhance that. In addition, miR-320a could suppress activity of 3'-untranslated region luciferase of metadherin (MTDH), a potent oncogene. The rescue experiment revealed that MTDH was a functional target of miR-320a. Moreover, we found that MTDH was negatively correlated with miR-320a expression, and it was related to clinical outcomes of breast cancer. Further xenograft experiment also showed that miR-320a could inhibit breast cancer metastasis in vivo. Our findings clearly demonstrate that miR-320a suppresses breast cancer metastasis by directly inhibiting MTDH expression. The present study provides a new insight into anti-oncogenic roles of miR-320a and suggests that miR-320a/MTDH pathway is a putative therapeutic target in breast cancer.

Neurokinin-1 activation affects EGFR related signal transduction in triple negative breast cancer.

Breast cancers bear overexpression of neurokinin-1 (NK-1). The aim of this study was to investigate the relationship between NK-1 and EGFR in triple negative breast cancers (TNBCs). Immunohistochemistry was performed to investigate NK-1 and EGFR expressions in TNBCs. [Sar(9), \Met(O2)(11)] substance P (SMSP) was used to activate NK-1 in two TNBC cell lines, MDA-MB-231 and MDA-MB-468. L-733060 and siRNA against NK-1 were used to inhibit NK-1. The in vitro regulatory effect of NK-1 was determined using CCK-8 proliferation assay. The effects of NK-1 activation and inhibition on EGFR and its downstreaming pathway were analyzed using western blot and real-time quantitative PCR. We found that the proportion of EGFR positive cases was increased with the increasement of NK-1 levels. SMSP could promote the proliferation of TNBC cells, while L-733060 and siRNA could inhibit cell proliferation and induce apoptosis. Moreover, SMSP could enhance expressions of phosphorylation (p)-EGFR and EGFR, and activate p-Akt and p-Erk. NK1-siRNA could decrease p-EGFR, p-Akt and p-Erk. In the presence of cetuximab (0.2mg/mL), SMSP still could stimulate cell proliferation, and activate p-EGFR. However, in the presence of erlotinib (10µM), SMSP could not stimulate cell proliferation and could not activate p-EGFR. Our study showed the interaction between NK-1 and EGFR in TNBCs. These results suggested that NK-1 may regulate TNBC proliferation through EGFR phosphorylation, and the curative effect of EGFR monoclonal antibodies may be affected by NK-1 activation.

H1foo is essential for in vitro meiotic maturation of bovine oocytes.

Oocyte-specific linker histone, H1foo, is localized on the oocyte chromosomes during the process of meiotic maturation, and is essential for mouse oocyte maturation. Bovine H1foo has been identified, and its expression profile throughout oocyte maturation and early embryo development has been established. However, it has not been confirmed if H1foo is indispensable during bovine oocyte maturation. Effective siRNAs against H1foo were screened in HeLa cells, and then siRNA was microinjected into bovine oocytes to down-regulate H1foo expression. H1foo overexpression was achieved via mRNA injection. Reverse transcription polymerase chain reaction (RT-PCR) results indicated that H1foo was up-regulated by 200% and down-regulated by 70%. Based on the first polar body extrusion (PB1E) rate, H1foo overexpression apparently promoted meiotic progression. The knockdown of H1foo significantly impaired bovine oocyte maturation compared with H1foo overexpression and control groups (H1foo overexpression = 88.7%, H1foo siRNA = 41.2%, control = 71.2%; P < 0.05). This decrease can be rescued by co-injection of a modified H1foo mRNA that has escaped from the siRNA target. However, the H1e (somatic linker histone) overexpression had no effect on PB1E rate when compared with the control group. Therefore we concluded that H1foo is essential for bovine oocyte maturation and its overexpression stimulates the process.

Mutation analysis of p63 gene in the first Chinese family with ADULT syndrome.

BACKGROUND: ADULT syndrome (acro-dermato-ungual-lacrimal-tooth syndrome) is a rare ectodermal dysplasia disorder known as autosomal dominant inheritance. Recent studies have linked p63 gene mutation to the development of this disease. However, the genetic characteristics of ADULT syndrome were still not well understood. METHODS: Mutation analysis of p63 gene in the first Chinese ADULT syndrome family was performed using direct DNA sequencing. RESULTS: The sequence analysis of exon 8 of p63 gene disclosed a heterozygous G>A substitution at nucleotide 893 (R298Q) in the proband. In addition, a single nucleotide polymorphism (SNP) rs16864880 in the downstream flanking region (DFR) of p63 exon 8 was also identified in this family. The proband and the paternal side including her father exhibited the C/G genotype at this position. The C/G variant frequency in the paternal was significantly higher as compared with the maternal (6/10 vs 0/6, P = 0.034). CONCLUSIONS: ADULT syndrome may be caused by the p63 gene mutation, and it might have closer genetic association with the paternal side in this family.

[HLA-DM gene polymorphism in Cantonese with condyloma acuminata].

OBJECTIVE: To study the polymorphism of HLA-DM gene in Cantonese patients with condyloma acuminata(CA) and determine the susceptible genetic factors of CA. METHODS: DMA and DMB typing was performed in 98 Cantonese patients with CA and 93 healthy controls using restriction fragment length polymorphism method. RESULTS: The gene frequencies of DMA*0101 and DMB*0101 were significantly higher in the patients than in the controls (P<0.05 and P<0.01, respectively), and gene frequency of DMA*0102 was lower in patients than in the controls (P<0.01). Genotype frequencies of HLA-DM showed no significant difference between CA patients and the controls (P>0.05). CONCLUSION: DMA*0101 and DMB*0101 alleles may be the susceptibility genes or closely linked to the susceptibility gene in Cantonese patients with CA.