Related Experiment Video
Updated: Jan 25, 2026
10:55
Purification of Ubiquitinated p53 Proteins from Mammalian Cells
Published on: March 21, 2022
2.7K
Relationship between p53 status and 5-fluorouracil sensitivity in 3 cell lines
Hiroaki Oka1, Kazumasa Ikeda, Hiromi Yoshimura
1Drug Safety Research Lab., Taiho Pharmaceutical Co. Ltd., 224-2 Ebisuno, Hiraishi, Kawauchi-cho, Tokushima, Japan. hiro-oka@taiho.co.jp
Mutation Research
|April 6, 2006
Summary
Mouse lymphoma cells (MOLY) showed higher sensitivity to 5-fluorouracil (5-FU) than human cells, with responses attributed to drug metabolism rather than p53 gene status. This study clarifies 5-FU
Area of Science:
- Toxicology
- Genetics
- Biochemistry
Background:
- Mouse lymphoma L5178Ytk+/- (MOLY) and human lymphoblastoid TK6 and WTK-1 cells are standard models for mutagenicity testing.
- MOLY and WTK-1 cells possess a mutated p53 gene, whereas TK6 cells do not, offering a basis for comparative analysis.
- 5-fluorouracil (5-FU) is a clastogen used in mutagenicity assays, and its differential effects across cell lines warrant investigation.
Purpose of the Study:
- To investigate whether differential responses to 5-fluorouracil (5-FU) in MOLY, TK6, and WTK-1 cells are linked to p53 gene status.
- To evaluate the impact of 5-FU on apoptosis and cell cycle distribution in these cell lines.
- To determine the activity of key 5-FU metabolizing enzymes in each cell line.
Main Methods:
- The Tk assay and in vitro micronucleus (MN) assay were employed to assess mutagenicity.
- 5-FU cytotoxicity, apoptosis frequency, and cell cycle distribution were analyzed.
- Activities of thymidylate synthetase (TS), dihydrouracil dehydrogenase (DPD), orotate phosphoribosyl transferase (OPRT), and thymidine phosphorylase (TP) were measured.
Main Results:
- MOLY cells exhibited increased mutation frequency (MF) and MN frequency, while WTK-1 cells showed increased MN frequency only. TK6 cells displayed no significant increase in MF or MN frequency.
- 5-FU demonstrated higher cytotoxicity in MOLY cells compared to human cell lines (lower IC50).
- Differential enzyme activities were observed: MOLY cells had higher OPRT and lower DPD/TP activity, suggesting enhanced 5-FU phosphorylation and reduced detoxification.
Conclusions:
- The heightened sensitivity and mutagenicity of MOLY cells to 5-FU are primarily driven by differences in drug metabolism, specifically increased phosphorylation and decreased detoxification, rather than p53 gene status.
- The study highlights the importance of considering metabolic enzyme activity when interpreting mutagenicity assay results.
- Findings suggest that MOLY cells are a more sensitive model for detecting 5-FU's genotoxic effects due to their metabolic profile.
Related Concept Videos
01:27Relationship Growth
210
Interpersonal relationships progress through stages, beginning with awareness and moving toward mutuality, where emotional connections deepen. While many relationships remain at moderate levels of mutuality, deeper connections form through self-disclosure, trust, and interdependence.Self-DisclosureSelf-disclosure involves revealing personal information, starting with surface-level details and gradually progressing to more intimate content. As trust grows, individuals feel more comfortable...
210
01:28Ending Relationships
177
The dissolution of intimate relationships presents complex emotional and psychological challenges, particularly when emotional bonds are strong, the relationship is long-standing, and perceived alternatives are limited. This distress often intensifies in romantic breakups, where the initiator may experience greater turmoil than the rejected partner. Contributing factors include residual attachment, guilt over causing pain, and uncertainty about how to manage the situation. The stress is further...
177
01:27Chemotherapy-Induced Nausea and Vomiting: 5-HT3 Receptor Antagonists
627
5-HT3 receptor antagonists, such as dolasetron, granisetron (Kytril), ondansetron (Zofran), and palonosetron (Axoli), are crucial in managing chemotherapy-induced nausea and vomiting (CINV) and postoperative nausea. These drugs selectively block 5-HT3 receptors in the visceral vagal and spinal afferent nerves, chemoreceptor trigger zone, and the vomiting center. They have a rapid onset of action and can be given as a single dose before chemotherapy. Ondansetron and granisetron, in particular,...
627
01:16Cell Lines
10.1K
A cell line is a population of cells grown in vitro that can be subcultured over several generations. Normal cells cease to divide after a certain number of cell divisions, a process known as replicative senescence. This number, called the Hayflick limit, was conceptualized by Leonard Hayflick in 1961 when he observed that fetal cells grown in culture could only divide 40-60 times. This limit is due to the shortening of the telomeres during each round of cell division, preventing cell division...
10.1K
02:12Relationship Formation
45.2K
What do you think is the single most influential factor in determining with whom you become friends and whom you form romantic relationships? You might be surprised to learn that the answer is simple: the people with whom you have the most contact. This most important factor is proximity. You are more likely to be friends with people you have regular contact with. For example, there are decades of research that shows that you are more likely to become friends with people who live in your dorm,...
45.2K
01:045-Number Summary
5.5K
In a dataset, the 5-number summary includes the minimum data value, the data value of the first quartile, the median data value or data value of the second quartile, the data value of the third quartile, and the maximum data value. These 5 data values can be visualized as a box and whisker plot.
In a box plot, the minimum and maximum data values represent the lower and upper whiskers in the graph, and the median is designated as the center of the box in the chart. The first quartile and third...
In a box plot, the minimum and maximum data values represent the lower and upper whiskers in the graph, and the median is designated as the center of the box in the chart. The first quartile and third...
5.5K