In this study,we identified the most deleterious nsSNP in RB1 gene through structural and functional properties of its protein (pRB) and investigated its binding affinity with E2F-2.Out of 956 SNPs,we investigated 12 ...In this study,we identified the most deleterious nsSNP in RB1 gene through structural and functional properties of its protein (pRB) and investigated its binding affinity with E2F-2.Out of 956 SNPs,we investigated 12 nsSNPs in coding region in which three of them (SNPids rs3092895,rs3092903 and rs3092905) are commonly found to be damaged by I-Mutant 2.0,SIFT and PolyPhen programs.With this effort,we modeled the mutant pRB proteins based on these deleterious nsSNPs.From a comparison of total energy,stabilizing residues and RMSD of these three mutant proteins with native pRB protein,we identified that the major mutation is from Glutamic acid to Glycine at the residue position of 746 of pRB.Further,we compared the binding efficiency of both native and mutant pRB (E746G) with E2F-2.We found that mutant pRB has less binding affinity with E2F-2 as compared to native type.This is due to sixteen hydrogen bonding and two salt bridges that exist between native type and E2F-2,whereas mutant type makes only thirteen hydrogen bonds and one salt bridge with E2F-2.Based on our investigation,we propose that the SNP with an id rs3092905 could be the most deleterious nsSNP in RB1 gene causing retinoblastoma.展开更多
AIM： TO study the effect of some genes especially those involved in cell cycle regulation on hepatocellular carcinoma. METHODS： Paraffin-embedded tissue samples of 25 patients （18 males and 7 females） with hepatoc...AIM： TO study the effect of some genes especially those involved in cell cycle regulation on hepatocellular carcinoma. METHODS： Paraffin-embedded tissue samples of 25 patients （18 males and 7 females） with hepatocellular carcinoma were collected from 22 pathology centers in Tehran during 2000-2001, and stained using immunohistochemistry method （avidin-biotin-peroxidase） for detection of p53, cyclinD1, RB1, c-los and N-ras proteins. RESULTS： Six （24%）, 5 （20%）, 12 （48%） and 2 samples （8%） were positive for p53, cyclinDl, C-los and N-ras expression, respectively. Twenty-two （88%） samples had alterations in the （31 cell-cycle checkpoint protein expression （RBI or cyclinD1）. P53 positive samples showed a higher （9 times） risk of being positive for RBI protein than p53 negative samples. Loss of expression of RBI in association with p53 over-expression was observed in 4 （66.7%） of 6 samples. Loss of expression of RBI was seen in all cyclinD1 positive, 20 （90.9%） N-ras negative, and ii （50%） C-fos positive samples, respectively. CyclinD1 positive samples showed a higher （2.85 and 4.75 times） risk of being positive for c-los and N-ras expression than cyclinD1 negative samples. CONCLUSION： The expression of p53, RB1 and c-los genes appears to have a key role in the pathogenesis of hepatocellular carcinoma in Iran. Simultaneous overexpression of these genes is significantly associated with their loss of expression during development of hepatocellular carcinoma.展开更多
Retinoblastoma (Rb) is the most common eye cancer in children and it can be inherited. Rb is quite rare and originators from the neural retina with a significant genetic component in etiology, which occurs in approxim...Retinoblastoma (Rb) is the most common eye cancer in children and it can be inherited. Rb is quite rare and originators from the neural retina with a significant genetic component in etiology, which occurs in approximately 1 in every 20 0000 births. In children with the heritable genetic form of Rb, there is a mutation on chromosome 13, called the retinoblastoma 1 (Rb1) gene. Early diagnosis and intervention is critical to the successful treatment of the Rb. The Rb1 gene is the first cloned tumor suppressor gene. As a negative regulator of the cell cycle, Rb1 gene could maintain a balance between cell growth and development through binding to transcription factors and regulating the expression of genes involved in cell proliferation and differentiation. Thus, it is involved in cell cycle, cell senescence, growth arrest, apoptosis and differentiation. We summarized the recent advances on the epidemiology and Rb1 gene of Rb in this review.展开更多
文摘In this study,we identified the most deleterious nsSNP in RB1 gene through structural and functional properties of its protein (pRB) and investigated its binding affinity with E2F-2.Out of 956 SNPs,we investigated 12 nsSNPs in coding region in which three of them (SNPids rs3092895,rs3092903 and rs3092905) are commonly found to be damaged by I-Mutant 2.0,SIFT and PolyPhen programs.With this effort,we modeled the mutant pRB proteins based on these deleterious nsSNPs.From a comparison of total energy,stabilizing residues and RMSD of these three mutant proteins with native pRB protein,we identified that the major mutation is from Glutamic acid to Glycine at the residue position of 746 of pRB.Further,we compared the binding efficiency of both native and mutant pRB (E746G) with E2F-2.We found that mutant pRB has less binding affinity with E2F-2 as compared to native type.This is due to sixteen hydrogen bonding and two salt bridges that exist between native type and E2F-2,whereas mutant type makes only thirteen hydrogen bonds and one salt bridge with E2F-2.Based on our investigation,we propose that the SNP with an id rs3092905 could be the most deleterious nsSNP in RB1 gene causing retinoblastoma.
文摘AIM： TO study the effect of some genes especially those involved in cell cycle regulation on hepatocellular carcinoma. METHODS： Paraffin-embedded tissue samples of 25 patients （18 males and 7 females） with hepatocellular carcinoma were collected from 22 pathology centers in Tehran during 2000-2001, and stained using immunohistochemistry method （avidin-biotin-peroxidase） for detection of p53, cyclinD1, RB1, c-los and N-ras proteins. RESULTS： Six （24%）, 5 （20%）, 12 （48%） and 2 samples （8%） were positive for p53, cyclinDl, C-los and N-ras expression, respectively. Twenty-two （88%） samples had alterations in the （31 cell-cycle checkpoint protein expression （RBI or cyclinD1）. P53 positive samples showed a higher （9 times） risk of being positive for RBI protein than p53 negative samples. Loss of expression of RBI in association with p53 over-expression was observed in 4 （66.7%） of 6 samples. Loss of expression of RBI was seen in all cyclinD1 positive, 20 （90.9%） N-ras negative, and ii （50%） C-fos positive samples, respectively. CyclinD1 positive samples showed a higher （2.85 and 4.75 times） risk of being positive for c-los and N-ras expression than cyclinD1 negative samples. CONCLUSION： The expression of p53, RB1 and c-los genes appears to have a key role in the pathogenesis of hepatocellular carcinoma in Iran. Simultaneous overexpression of these genes is significantly associated with their loss of expression during development of hepatocellular carcinoma.
文摘Retinoblastoma (Rb) is the most common eye cancer in children and it can be inherited. Rb is quite rare and originators from the neural retina with a significant genetic component in etiology, which occurs in approximately 1 in every 20 0000 births. In children with the heritable genetic form of Rb, there is a mutation on chromosome 13, called the retinoblastoma 1 (Rb1) gene. Early diagnosis and intervention is critical to the successful treatment of the Rb. The Rb1 gene is the first cloned tumor suppressor gene. As a negative regulator of the cell cycle, Rb1 gene could maintain a balance between cell growth and development through binding to transcription factors and regulating the expression of genes involved in cell proliferation and differentiation. Thus, it is involved in cell cycle, cell senescence, growth arrest, apoptosis and differentiation. We summarized the recent advances on the epidemiology and Rb1 gene of Rb in this review.
