Objective To study the effects of midkine (MK) gene-targeting small interfering RNA (siRNA)on the invasion of melanoma cells.Methods Three MK gene-targeting siRNAs (S1,S2 and S3)were designed,constructed,and transfected into human A375 melanoma cells.Real-time PCR was performed to measure the expression of MK gene and to screen the siRNA with best efficacy.Then,A375 cells were transfected with the optimal siRNA of various doses (3.125,6.25 and 12.5 nmol/L)followed by additional culture of various durations(24,48,72 hours).Some A375 cells remaining untreated served as the blank control group,and some transfected only with liposomes served as the vector control group.Reverse transcription (RT) -PCR and Western blot were conducted to detect the mRNA and protein expression of MK,respectively,MTT assay to observe the adhesion of A375 cells,and Boyden chamber was used to evaluate cell invasion.Results The expression of MK mRNA was downregulated by all the three siRNAs,especially by the siRNA S3,which was used in the following transfection experiment.Real-time quantitative PCR revealed that the MK mRNA expression was reduced by the siRNA in a dose- (r24hours=-0.906,r4Bhours=-0.922,r72hours=-0.939,all P<0.01)and time-dependent(r3.125nmol/L=-0.889,r625nmol/L=-0.935,r125nmol/L=-0.928,all P<0.01)manner.MTT assay showed that the percentage of adhesing cells was 73.66%±2.25%,49.36%±2.16%and 28.35%±1.68%in A375 cells transfected with the siRNA of 3.125,6.25 and 12.5 nmol/L,respectively.The number of cells migrating across the chamber filter was 23.9±1.6,12.1±1.5,5.6±1.2 among A375 cells transfected with the siRNA of 3.125,6.25 and 12.5 nmol/L,respectively,significantly lower than that in the blank control group(36.8±1.5).The percentage of adhesing cells and number of migrating cells decreased with the dose of siRNA(r=-0.936,-0.915,P<0.01,0.05,respectively).Conclusions MK gene might play an important role in the adhesion and invasion of melanonla cells.To down-regulate the expression of MK gene by siRNA may suppress the adhesion and invasion of melanoma cells.

Ring dermoid of cornea (RDC) is an autosomal dominant disorder of cornea. The previous study identified a G185A mutation of PITX2 gene in a Chinese family with RDC. To investigate the pathological mechanism of PITX2 R62H mutation, a PITX2 prokaryotic expression plasmid were constructed and GST-PITX2 fusion protein were purified. EMSA was further conducted. The DNA-banding ability of PITX2 R62H was similar to that of the wild type PITX2 were found. The cell lines stably expressed PITX2 was also generated, and cell cycle were analyzed by flow cytometry, and the expression of ?-catenin and Cyclin D1 were detected by quantitative Real-time PCR. The results showed that proliferating ability of cells expressing PITX2 R62H was lower than that of cells expressing PITX2 WT, as well as ?-catenin and Cyclin D1 mRNA level. These findings revealed that PITX2 R62H mutation affected the Wnt/?-catenin→PITX2 pathway, promoted the genes expressing abnormally, and led to abnormal cell proliferation and the formation of RDC, which may play an important role in pathogenesis of RDC.

Objective To investigate the potential risk factors for mild cognitive impairment (MCI) in the elderly population in the community, and to provide a basis for the primary prevention of MCI. Methods A cross-sectional study of elderly population in communities of Shanghai, China was conducted. A total of 368 subjects including both males and females, aged 65-80 years old, were selected to complete the mini-mental state examination (MMSE), basic information questionnaires, and physical examinations. Logistic regression analysis was used to analyze the potential risk factors of MCI. Results Of the 368 subjects participating in the study, 53 were found to have MCI and the prevalence rate was 14.4%. Univariate analysis found that older age, low education, no folic acid supplementation, stroke, osteoporosis and hyperlipidemia were risk factors of MCI. Multiple logistic regression analysis showed that advanced age [OR=1.146 (95%CI: 1.052-1.249)] and osteoporosis [OR=2.371 (95%CI: 1.042-5.396)] were the independent risk factors for MCI, while higher education [OR=0.073 (95%CI: 0.011-0.478)] was a protective factor. Age influenced all the aspects of MMSE scores (all P values <0.05). In addition, the analysis of the results suggested that subjects with regular folic acid supplementation got higher MMSE scores, especially in the aspect of language and praxis (P=0.002). On the contrary, patients with osteoporosis had lower attention and computing power scores (P=0.022). Conclusion The prevalence of MCI increased with age. Low education and osteoporosis may be the independent risk factors for MCI in the elderly population. Although no association was observed between folic acid supplementation and MCI, folic acid supplementation could improve the performance of language and praxis.