G四重复体是BRCA2缺陷颗粒细胞原始体和脑髓母细胞瘤的脆弱性来源
Danielle L Keahi1, Mathijs A Sanders2,3, Matthew R Paul4
1Laboratory of Genome Maintenance, The Rockefeller University, New York, NY, USA.
bioRxiv : the preprint server for biology
|August 2, 2024
概括
大脑小细胞中的BRCA2缺乏会在G-四重复中造成DNA损伤,导致脑髓母细胞瘤. 在瘤中PIF1基酶的升级表明它存在.
科学领域:
- 遗传学 是一个遗传学.
- 癌症生物学 癌症生物学
- 神经科学是一个神经科学.
背景情况:
- 在BRCA2中双性致病变体导致Fanconi贫血 (FA-D1),使患者易患胚胎瘤,如脑髓母细胞瘤.
- 在FA-D1患者中,心膜母细胞瘤通常是由小脑颗粒细胞前体 (GCP) 引起的,这些细胞在SHH激活下迅速增殖.
- 需要BRCA2功能来防止GCP瘤发生的特定DNA病变仍然未被确定.
研究的目的:
- 为了识别需要在GCP中BRCA2功能以预防脑髓母细胞瘤的DNA病变.
- 为了研究G-四复合体 (G4s) 在BRCA2缺陷脑髓母细胞瘤的发病过程中的作用.
主要方法:
- 使用了一种有条件Brca2删除在中枢神经系统和全球Trp53损失的小鼠模型.
- 在瘤上进行全基因组测序,以确定结构变异.
- 用G4稳定剂评估了GCP复制速度,并分析了脑髓母细胞瘤细胞中的Pif1螺旋酶功能.
主要成果:
- 缺乏Brca2;Trp53的小鼠开发了完全穿透的SHH髓母细胞瘤.
- 瘤断点在G-四重复区域中得到了丰富,这表明G4s是不稳定的地点.
- Brca2 缺乏的 GCP 显示 G4 稳定剂的复制速度降低,瘤中的 Pif1 上调促进了 G4 解析.
结论:
- 在繁殖的GCP中,G-四重复合体可能是复制停滞的地点.
- BRCA2 缺乏导致G4诱导的基因组不稳定性,促进脑髓母细胞瘤.
- 在瘤中,PIF1螺旋酶被上调以消除G4s,这对BRCA2缺乏的脑髓母细胞瘤来说是一个潜在的治疗标.
相关概念视频
The Retinoblastoma Gene
4.1K
Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable damage. Hence, they play an essential role in preventing the proliferation of damaged cells.
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
4.1K
Abnormal Proliferation
4.5K
Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the...
4.5K
Mismatch Repair
4.8K
Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes.
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
4.8K
Fixing Double-strand Breaks
12.5K
The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...
12.5K
DNA Damage can Stall the Cell Cycle
9.1K
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
9.1K
Negative Regulator Molecules
35.3K
Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
35.3K


