RESUMO
Background and purpose:Insulin-like growth factor-1 (IGF-1) is a peptide that participates in many biological processes by stimulating the downstream signaling pathways through their interaction with IGF-1 re-ceptor (IGF-1R) and insulin receptor (IR). Bone morphogenetic proteins (BMPs) are a group of functional proteins which participate in the biological processes of proliferation and migration in many kinds of cancers and have become a hot area of cancer research. The study aimed to investigate the effects of silencingIGF-1R gene on the expression level ofBMP2 gene, and the cell proliferation and apoptosis of SMMC7721 cells.Methods:The RNAi plasmid targetingIGF-1R gene was constructed and transfected into SMMC7721 cells. Then the inhibition effect on the expression level of IGF-1R and BMP2 gene was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. The SMMC7721 growth curve and cell apoptosis were detected by MTT assay and flow cytometry after they were transfected with RNAi plasmid.Results:The RNAi plasmid targetingIGF-1R gene was constructed successfully. The inhibition efficiencies at mRNA expression levels were 68.9% and 80.7% (IGF-1R gene), 79.5% and 83.3% (BMP2 gene), respectively, after transfection with IGF-1R-siRNA-1 and IGF-1R-siRNA-2 plasmid (P<0.05). The inhibition efficiencies at protein levels were 46.1% and 62.1% (IGF-1R gene,P<0.05), 42.5% and 60.9% (BMP2 gene,P<0.05), respectively. The results of MTT growth curve showed that the proliferation rate in the transfected SMMC7721 cells was significantly slower than that in the control group (P<0.05). The proportion of apoptotic cells in transfected groups was significantly higher than that in the control group (P<0.05).Conclusion:SilencingIGF-1R gene can downregulate the expression ofBMP2 gene at different levels that results in inhibition of cell proliferation and promotion of apoptosis in SMMC7721 cells.
RESUMO
A 15q25-qter partial trisomy characterized by pre or postnatal overgrowth, tall stature, macrocephaly and craniosynostosis has rarely been reported. The cause of overgrowth has been thought to be the triplication of the insulin-like growth factor 1 receptor (IGF1R) gene located on the 15q26.3. We report a patient with partial trisomy 15q25.3-qter showing mental retardation, developmental delay, macrocephaly, long narrow face, ptosis, high palate arch, scoliosis, clinodactyly and overgrowth. Additional material located on terminal 2q was found in karyotyping analysis. In bacterial artificial chromosome (BAC) clone-based-array comparative genomic hybridization (aCGH) analysis, a gain of 31 clones on 15q25.3-qter and a loss of 2 clones on 2q37.3 were observed. An extra copy of IGF1R gene was observed on derivative chromosome 2 in FISH analysis. In conclusion, the patient was diagnosed to have de novo 46,XX,der(2)t(2;15)(q37.3;q25.3) chromosome complement. Adequate genetic counseling and regular follow-ups would be needed for the patient.