Inverse Association Between Cyclin D1 Overexpression and Retinoblastoma Gene Mutation in Thyroid Carcinomas

Endocrine ◽  
1998 ◽  
Vol 8 (1) ◽  
pp. 61-64 ◽  
Author(s):  
Minjing Zou ◽  
Yufei Shi ◽  
Nadir R. Farid ◽  
Sultan T. Al-Sedairy
Keyword(s):  
Cyclin D1 ◽  
Gene Mutation ◽  
Inverse Association ◽  
Retinoblastoma Gene ◽  
Thyroid Carcinomas

Cyclin D1 Overexpression in Thyroid Carcinomas: Relation with Clinico-Pathological Parameters, Retinoblastoma Gene Product, and Ki67 Labeling Index

Thyroid ◽  
2000 ◽  
Vol 10 (9) ◽  
pp. 741-746 ◽  
Author(s):  
Fulvio Basolo ◽  
Maria A. Caligo ◽  
Aldo Pinchera ◽  
Franco Fedeli ◽  
Andrea Baldanzi ◽  
...  
Keyword(s):  
Cyclin D1 ◽  
Gene Product ◽  
Labeling Index ◽  
Retinoblastoma Gene ◽  
Thyroid Carcinomas ◽  
Ki67 Labeling Index ◽  
Retinoblastoma Gene Product

scholarly journals DNA tumor virus oncoproteins and retinoblastoma gene mutations share the ability to relieve the cell's requirement for cyclin D1 function in G1.

1994 ◽  
Vol 125 (3) ◽  
pp. 625-638 ◽  
Author(s):  
J Lukas ◽  
H Müller ◽  
J Bartkova ◽  
D Spitkovsky ◽  
A A Kjerulff ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Complex Formation ◽  
Cyclin D1 ◽  
Cell Lines ◽  
T Antigen ◽  
Regulatory Function ◽  
Retinoblastoma Gene ◽  
Checkpoint Control ◽  
Wild Type ◽  
In Cells

The retinoblastoma gene product (pRB) participates in the regulation of the cell division cycle through complex formation with numerous cellular regulatory proteins including the potentially oncogenic cyclin D1. Extending the current view of the emerging functional interplay between pRB and D-type cyclins, we now report that cyclin D1 expression is positively regulated by pRB. Cyclin D1 mRNA and protein is specifically downregulated in cells expressing SV40 large T antigen, adenovirus E1A, and papillomavirus E7/E6 oncogene products and this effect requires intact RB-binding, CR2 domain of E1A. Exceptionally low expression of cyclin D1 is also seen in genetically RB-deficient cell lines, in which ectopically expressed wild-type pRB results in specific induction of this G1 cyclin. At the functional level, antibody-mediated cyclin D1 knockout experiments demonstrate that the cyclin D1 protein, normally required for G1 progression, is dispensable for passage through the cell cycle in cell lines whose pRB is inactivated through complex formation with T antigen, E1A, or E7 oncoproteins as well as in cells which have suffered loss-of-function mutations of the RB gene. The requirement for cyclin D1 function is not regained upon experimental elevation of cyclin D1 expression in cells with mutant RB, while reintroduction of wild-type RB into RB-deficient cells leads to restoration of the cyclin D1 checkpoint. These results strongly suggest that pRB serves as a major target of cyclin D1 whose cell cycle regulatory function becomes dispensable in cells lacking functional RB. Based on available data including this study, we propose a model for an autoregulatory feedback loop mechanism that regulates both the expression of the cyclin D1 gene and the activity of pRB, thereby contributing to a G1 phase checkpoint control in cycling mammalian cells.

scholarly journals Prognostic significance of retinoblastoma gene mutation in retinoblastoma eye with respect to pathological risk factors

2013 ◽  
Vol 05 (03) ◽  
pp. 411-418 ◽  
Author(s):  
Asad Aslam Khan ◽  
Riffat Mehboob ◽  
Mulazim Hussain Bukhari
Keyword(s):  
Risk Factors ◽  
Gene Mutation ◽  
Prognostic Significance ◽  
Retinoblastoma Gene
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