The DOI matches its Crossref record.
Gene Amplification and Drug Resistance in Cultured Murine Cells
Abstract
Resistance of mouse cells to the folate analog, methotrexate, results from selection of increasingly resistant cells on progressive increases of methotrexate in the culture medium. High-level resistance is associated with high rates of synthesis of dihydrofolate reductase and correspondingly high numbers of reductase genes. In some variants high resistance and gene copy number are stable in the absence of selection pressure, whereas in others they are unstable. Analogies are made to antibiotic and insecticide resistance wherein selection of organisms with increased capacity to counteract the drug effect results in emergence of resistance. Gene amplification may underlie many such resistance phenomena.
Overview
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Verification
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Citations
Cited by
Combinatorial drug therapy for cancer in the post-genomic era
Al-Lazikani, B., Banerji, U., & Workman, P. (2012) · Nature Biotechnology · doi:10.1038/nbt.2284 · Cited by 1,070
Isolation of Chinese hamster cell mutants deficient in dihydrofolate reductase activity
Urlaub, G., & Chasin, L. A. (1980) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.77.7.4216 · Cited by 876
Chromosome aberrations in solid tumors
Albertson, D. G., Collins, C., McCormick, F., & Gray, J. W. (2003) · Nature Genetics · doi:10.1038/ng1215 · Cited by 812
Lee, F., Mulligan, R., Berg, P., & Ringold, G. (1981) · Nature · doi:10.1038/294228a0 · Cited by 466
Schwab, M., Alitalo, K., Varmus, H. E., Bishop, J. M., & George, D. (1983) · Nature · doi:10.1038/303497a0 · Cited by 458
Metadata
- Authors
- Schimke, R. T., Kaufman, R. J., Alt, F. W., & Kellems, R. F.
- Venue
- Science
- Published
- 1978-12-08
- Volume
- 202
- Issue
- 4372
- Pages
- 1051-1055
- ISSN
- 0036-8075 (ISSN-L)
- 1095-9203
- OpenAlex
- W2036518418
- Cited by
- 314
- References
- 0
- FWCI
- 17.76
- Type
- journal article
- Language
- en
- Open access
- closed
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
How to cite
Cite CoChat for the checks on this page, and the paper for its own findings.
- This page
- CoChat. (2026). Citation check: Gene Amplification and Drug Resistance in Cultured Murine Cells. https://app.cochat.ai/papers/10.1126/science.715457
- The paper
- Schimke, R. T., Kaufman, R. J., Alt, F. W., & Kellems, R. F. (1978). Gene Amplification and Drug Resistance in Cultured Murine Cells. Science. https://doi.org/10.1126/science.715457
Data sources
Bibliographic data: Semantic Scholar, OpenAlex, Crossref.
Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).
Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.
