CD147 stimulates hepatoma cells escaping from immune surveillance of T cells by interaction with Cyclophilin A.

T cells play an important role in tumor immune surveillance. CD147 is a member of immunoglobulin superfamily present on the surface of many tumor cells and mediates malignant cell behaviors. Cyclophilin A (CypA) is an intracellular protein promoting inflammation when released from cells. CypA is a natural ligand for CD147. In this study, CD147 specific short hairpin RNAs (shRNA) were transfected into murine hepatocellular carcinoma Hepa1-6 cells to assess the effects of CD147 on hepatoma cells escaping from immune surveillance of T cells. We found extracellular CypA stimulated cell proliferation through CD147 by activating ERK1/2 signaling pathway. Downregulation of CD147 expression on Hepa1-6 cells significantly suppressed tumor progression in vivo, and decreased cell viability when co-cultured with T cells in vitro. Importantly, knockdown of CD147 on Hepa1-6 cells resulted in significantly increased T cells chemotaxis induced by CypA both in vivo and in vitro. These findings provide novel mechanisms how tumor cells escaping from immune surveillance of T cells. We provide a potential therapy for hepatocellular carcinoma by targeting CD147 or CD147-CypA interactions.

Development of noninvasive prenatal diagnosis of trisomy 21 by RT-MLPA with a new set of SNP markers.

INTRODUCTION: Placental mRNA can now be detected in maternal whole blood, raising the possibility of using maternal blood for noninvasive prenatal diagnosis (NIPD) of trisomy 21. We aimed to identify new mRNA-single nucleotide polymorphism (mRNA-SNP) markers suitable for use in reverse-transcriptase multiplex ligation-dependent probe amplification (RT-MLPA) to develop a more reliable diagnostic method for trisomy 21 in Chinese subjects. MATERIALS AND METHODS: Using sequencing, we determined the status of SNPs in genes expressed in the placenta and calculated their heterozygote frequencies to determine which loci were suitable for use in RT-MLPA. Cell-free fetal RNA was extracted from peripheral blood samples of 246 women at 12-24 weeks of pregnancy, and the SNP loci selected were analyzed by RT-MLPA, followed by capillary electrophoresis. Karyotype analyses were used to confirm the diagnosis of trisomy 21. RESULTS: As compared with karyotype analysis, the diagnostic sensitivity and specificity of RT-MLPA were excellent (95 and 100% in different gestational weeks). CONCLUSION: The RT-MLPA technique is a suitable and reliable method for the diagnosis of trisomy 21. Use of RT-MLPA with the SNP markers described here shows good specificity, high sensitivity, and high throughput potential, making this technique suitable for NIPD in clinical practice.

[Secretory expression vector V-pLNCX-s-hri inhibits the growth of mouse B16 melanoma].

BACKGROUND AND OBJECTIVE: Human ribonuclease inhibitor (hRI) extracted and purified from human placenta has been shown to remarkably inhibit some solid tumors in mice. This study was to construct V-pLNCX-s-hri, a secretory expression vector, and explore its inhibition effects on the growth of mouse B16 melanoma cells. METHODS: The hRI gene sequence conjugated with the synthesized signal peptide of mouse IgG was cloned into the retroviral vector V-pLNCX to construct V-pLNCX-s-hri. The PA317 cells were used for viral package and NIH3T3 cells were employed to determine the viral titer. The expression of hRI gene was detected by RT-PCR and Western blot. The content of RI was determined by enzyme-linked immunoabsorption assay (ELISA). The model of B16 melanoma-carrying mouse was established and received different treatments. The tumor weight and microvessle density (MVD) were assessed. Normal saline (NS), V-pLNCX, and V-pLNCX-hri were used as controls. RESULTS: The infection efficiency of V-pLNCX-s-hri on cultured B16 cells reached 38.5%. mRNA and protein levels of hRI were detected in B16 cells infected by V-pLNCX-s-hri. The hRI content in the supernatant of infected B16 cells reached 0.228 microg/mL. The hRI content in the peripheral blood of experimental mice was significantly higher in the V-pLNCX-s-hri group (0.249 microg/mL) than in the NS group (0.035 microg/mL), V-pLNCX group (0.028 microg/mL) and V-pLNCX-hri group (0.169 microg/mL) (P<0.01). The tumor weight and MVD were significantly lower in the V-pLNCX-s-hri group compared with those in the NS, V-pLNCX and V-pLNCX-hri groups (P>0.01). CONCLUSIONS: V-pLNCX-s-hri can effectively infect B16 cells and induce high expression of hRI. V-pLNCX-s-hri is superior to V-pLNCX-hri in inhibiting the growth of B16 cells.