[Effect of LMO2 overexpression in hemangioblast on its proliferation and hematopoietic differentiation].

OBJECTIVE: To investigate function of the Lim-only protein(LMO2) in hemangioblast generated from murine embryonic stem cells differentiation to hematopoietic cells. METHODS: The hemangioblast-specific expression vector with lmo2 or green fluorescence protein gene was constructed, respectively. The murine embryonic stem cells were transfected by the hemangioblast-specific expression vectors. The neomycin-resistance ES cell clones were obtained after having been screened by G418. The cell clones were spontaneously differentiated into embryo bodies(EB) containing hemangioblast.Expression of the hematopoietic genes was investigated by real-time reverse transcription-ploymerase chain reaction during EB differentiation.For the EB cells, blast-cloning forming cells analysis and blood-colony forming unit analysis were then performed, respectively. The numbers of the blasts were counted during hematopoietic differentiation. RESULTS: The hemangioblast-specific expression vector with lmo2 or green fluorescence protein was transfected into ES cells.The neomycin-resistance ES cells generated EBs from 2.5 days to 10 days.Real time reverse transcription-ploymerase chain reaction analysis indicated that overexpression of lmo2 increased the expression of hematopoietic genes(gata1, tal1, Β-h1, and Β-major globin) during EB formation.Blast-cloning forming cells analysis showed that the numbers of the blasts generated by ES/lmo2 was 2-or 3-fold than those in the controls.The total numbers of the blood-colony forming unit or the numbers of the erythrocyte colony-forming unit generated by ES/lmo2 were 2.5 times or 3 times, respectively, when compared with the controls. CONCLUSION: LMO2 enhances the proliferation and differentiation of hemangioblasts.

Association analyses identify three susceptibility Loci for vitiligo in the Chinese Han population.

To identify susceptibility loci for vitiligo, we extended our previous vitiligo genome-wide association study with a two-staged replication study that included 6,857 cases and 12,025 controls from the Chinese Han population. We identified three susceptibility loci, 12q13.2 (rs10876864, P(combined)=8.07 × 10(-12), odds ratio (OR)=1.18), 11q23.3 (rs638893, P(combined)=2.47 × 10(-9), OR=1.22), and 10q22.1 (rs1417210, P(combined)=1.83 × 10(-8), OR=0.88), and confirmed three previously reported loci for vitiligo, 3q28 (rs9851967, P(combined)=8.57 × 10(-8), OR=0.88), 10p15.1 (rs3134883, P(combined)=1.01 × 10(-5), OR=1.11), and 22q12.3 (rs2051582, P(combined)=2.12 × 10(-5), OR=1.14), in the Chinese Han population. The most significant single-nucleotide polymorphism in the 12q13.2 locus is located immediately upstream of the promoter region of PMEL, which encodes a major melanocyte antigen and has expression loss in the vitiligo lesional skin. In addition, both 12q13.2 and 11q23.3 loci identified in this study are also associated with other autoimmune diseases such as type 1 diabetes and systemic lupus erythematosus. These findings provide indirect support that vitiligo pathogenesis involves a complex interplay between immune regulatory factors and melanocyte-specific factors. They also highlight similarities and differences in the genetic basis of vitiligo in Chinese and Caucasian populations.

Association analyses identify six new psoriasis susceptibility loci in the Chinese population.

We extended our previous genome-wide association study for psoriasis with a multistage replication study including 8,312 individuals with psoriasis (cases) and 12,919 controls from China as well as 3,293 cases and 4,188 controls from Germany and the United States and 254 nuclear families from the United States. We identified six new susceptibility loci associated with psoriasis in the Chinese study containing the candidate genes ERAP1, PTTG1, CSMD1, GJB2, SERPINB8 and ZNF816A (combined P < 5 × 10⁻8) and replicated one locus, 5q33.1 (TNIP1-ANXA6), previously reported (combined P = 3.8 × 10⁻²¹) in the European studies. Two of these loci showed evidence for association in the German study at ZNF816A and GJB2 with P = 3.6 × 10⁻³ and P = 7.9 × 10⁻³, respectively. ERAP1 and ZNF816A were associated with type 1 (early onset) psoriasis in the Chinese Han population (test for heterogeneity P = 6.5 × 10⁻³ and P = 1.5 × 10⁻³, respectively). Comparisons with the results of previous GWAS of psoriasis highlight the heterogeneity of disease susceptibility between the Chinese and European populations. Our study identifies new genetic susceptibility factors and suggests new biological pathways in psoriasis.

Gefitinib-sensitive mutations of the epidermal growth factor receptor tyrosine kinase domain in chinese patients with non-small cell lung cancer.

PURPOSE: Studies have shown that mutations in the epidermal growth factor receptor (EGFR) tyrosine kinase domain are associated with response of lung cancer to gefitinib (Iressa, AstraZeneca Corp., Shanghai, China). A higher incidence of EGFR mutation was observed in non-small cell lung cancer (NSCLC) patients of Japanese origin compared with those of American origin. However, no data about such mutations in Chinese patients with NSCLC could be obtained. METHODS: Primary NSCLC tissues were obtained for analysis of mutations in exons 18 to 21 of EGFR from a total of 76 patients, of whom 54 did not receive gefitinib therapy and 22 did. PCR products were sequenced directly and mutations were confirmed by an independent PCR and sequence analysis. All types of mutation were cloned and sequenced. RESULTS: A total of 10 types of mutation were found in the series of patients, including two different silent mutations in exon 20 from 11 patients. More than half of the silent mutations (6 of 11) in exon 20 coexisted with other mutations. Mutations were more frequent in adenocarcinoma (17 of 35; 48.6%) compared with squamous carcinoma (1 of 19; 5.3%) among untreated patients. Similar mutations were observed in all seven gefitinib-treated patients with partial response, and no mutations were detected in all eight patients with progressive disease (P < 0.001), except two silent mutations. Three mutations were observed in seven patients with stable disease. CONCLUSIONS: Mutations in the epidermal growth factor receptor tyrosine kinase domain in lung adenocarcinomas from Chinese patients were more frequent than reported previously in lung adenocarcinomas from American patients. Such mutations were well correlated with tumor response to gefitinib.