CoChat
Sign Up
Cited by 655Lung Cancer Treatments and MutationsLung Cancer Research StudiesCancer Genomics and Diagnostics

RB loss in resistant EGFR mutant lung adenocarcinomas that transform to small-cell lung cancer

Open access
Niederst, Matthew J., Sequist, Lecia V., Poirier, John T., Mermel, Craig H., Lockerman, Elizabeth L., Garcia, Angel R., Katayama, Ryohei, Costa, Carlotta +19 more·2015·Nature Communications
DOI 10.1038/ncomms7377PMC PMC4357281
Open this paper in CoChat — free accountOpen PDF

Abstract

Tyrosine kinase inhibitors are effective treatments for non-small-cell lung cancers (NSCLCs) with epidermal growth factor receptor ( EGFR ) mutations. However, relapse typically occurs after an average of 1 year of continuous treatment. A fundamental histological transformation from NSCLC to small-cell lung cancer (SCLC) is observed in a subset of the resistant cancers, but the molecular changes associated with this transformation remain unknown. Analysis of tumour samples and cell lines derived from resistant EGFR mutant patients revealed that Retinoblastoma (RB) is lost in 100% of these SCLC transformed cases, but rarely in those that remain NSCLC. Further, increased neuroendocrine marker and decreased EGFR expression as well as greater sensitivity to BCL2 family inhibition are observed in resistant SCLC transformed cancers compared with resistant NSCLCs. Together, these findings suggest that this subset of resistant cancers ultimately adopt many of the molecular and phenotypic characteristics of classical SCLC.

AI snapshot

Written from the paper’s full text.

TL;DR

In EGFR-mutant lung adenocarcinomas that transform to small-cell lung cancer after TKI resistance, RB is universally lost and tumors adopt SCLC-like gene expression, lose EGFR, and become sensitive to BCL-2 family inhibition. RB loss appears necessary but not sufficient for this transformation.

Key findings

  • RB loss was universal in SCLC-transformed resistant cancers: IHC showed complete loss in all 10 resistant SCLC samples, and the Discussion states RB was lost in 11/11 SCLC-transformed samples; RB expression was intact in all but 1 of 11 resistant NSCLC controls (P<0.0001, Fisher’s exact test).
  • SCLC-transformed tumors and cell lines lost EGFR expression: IHC showed marked EGFR decrease in 7 resistant SCLC cases versus baseline, while EGFR was intact in 10 resistant NSCLC cases; MGH131-1 and MGH131-2 cells lacked EGFR protein and were resistant to gefitinib and WZ4002.
  • SCLC-transformed cells resembled classical SCLC and were sensitive to ABT-263: they clustered with classical SCLC lines by RNA/miRNA expression, and MGH131-1/MGH131-2 were among the most sensitive of 21 classical SCLC cell lines to ABT-263; ABT-263 was significantly more active than gefitinib in these cells.
  • In patient #7, two SCLC lesions shared 291 mutations with each other versus 73 and 57 shared with the NSCLC lesion; both SCLC samples had PIK3CA activating mutation, TP53 loss/inactivating mutation, and bi-allelic RB1 loss, with EGFR variant allele frequencies of 66% and 77%. RB loss alone was insufficient: RB knockdown did not alter gefitinib sensitivity, and RB-deficient adenocarcinomas were observed.

Methods

  • Retrospective repeat-biopsy cohort of EGFR-mutant NSCLC patients biopsied before and after erlotinib resistance over 2005–2013; analyses included 11 SCLC-transformed samples from 9 patients and 11 resistant NSCLC controls, plus patient-derived cell lines such as MGH131-1 and MGH131-2.
  • Molecular and phenotypic profiling used WES, array CGH, qPCR, RB/EGFR IHC, RNA expression microarrays, miRNA assays, methylation beadchip, CellTiter-Glo viability assays, shRNA-mediated RB knockdown, and in vitro/in vivo gefitinib-resistance models.
  • RB IHC comparison between transformed SCLC and resistant NSCLC controls was tested by Fisher’s exact test.

Limitations

  • Stated: the authors cannot rule out that EGFR-mutant SCLC pre-existed before TKI treatment, although they argue this is unlikely because biopsies sample only a minute fraction of tumor burden and the SCLCs progressed rapidly clinically.
  • Stated: insufficient tissue from remaining samples prevented genetic analyses in the larger cohort, so IHC was used to assess RB expression; RB loss was necessary but not sufficient in their models, and knockdown studies in established cell lines may not capture in vivo pluripotent cells.
  • Evident: the transformed cohort is small (9 patients), the study is retrospective and single-institution, and it lacks direct functional proof that RB loss causes transformation.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1038/ncomms7377

Cites

39 of 39 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 19 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    Increased neuroendocrine marker expression is observed in resistant SCLC transformed cancers compared with resistant NSCLCs.

    “increased neuroendocrine marker and decreased EGFR expression as well as greater sensitivity to BCL2 family inhibition are observed in resistant SCLC transformed cancers compared with resistant NSCLCs.”
    Quote in the paperSubstantial claim
  • Findingown data

    Decreased EGFR expression is observed in resistant SCLC transformed cancers compared with resistant NSCLCs.

    “increased neuroendocrine marker and decreased EGFR expression as well as greater sensitivity to BCL2 family inhibition are observed in resistant SCLC transformed cancers compared with resistant NSCLCs.”
    • Also stated in: § Resistant transformed SCLCs lose EGFR expression · plain
      “there was a marked decrease in EGFR expression in the SCLC resistant tumours compared with baseline, but EGFR expression was intact in resistant EGFR mutant NSCLCs.”
    Quote in the paperSubstantial claim
  • Findingcitation

    Classical SCLC cell lines have significantly reduced levels of EGFR mRNA compared with adenocarcinoma cell lines.

    “interrogation of the expression data from the cancer cell line encyclopedia20 (CCLE) database revealed that classical SCLC cell lines have significantly reduced levels of EGFR mRNA compared with adenocarcinoma cell lines”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [20] Barretina, J. et al. The Cancer Cell Line Encyclopedia enables predictive modelling of anticancer drug sensitivity. Nature 483, 603–607 (2012) . source

      Not checked in the free run.

  • Findingown data

    The MGH125 cell line also lacks RB expression.

    “Notably, the MGH125 cell line (patient #8) also lacks RB expression.”
    Quote in the paperSubstantial claim
  • Findingown data

    Both SCLC transformed cell lines were highly resistant to gefitinib and the third-generation EGFR inhibitor WZ4002.

    “Cell viability assays indicated that both SCLC transformed cell lines were highly resistant to gefitinib as well as the third-generation EGFR inhibitor, WZ4002”
    Quote in the paperSubstantial claim
  • May combine two claims. 20
  • The quote only partly states this claim. 1
  • Classified as probably not a substantial claim. 8

  • May combine two claims.

    Findingown data

    There is a marked decrease in EGFR expression in SCLC resistant tumours compared with baseline, but EGFR expression is intact in resistant EGFR mutant NSCLCs.

    “there was a marked decrease in EGFR expression in the SCLC resistant tumours compared with baseline, but EGFR expression was intact in resistant EGFR mutant NSCLCs.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    RB is lost in all SCLC transformed resistant EGFR mutant cases, but rarely in resistant EGFR mutant cancers that remain NSCLC.

    “Analysis of tumour samples and cell lines derived from resistant EGFR mutant patients revealed that Retinoblastoma (RB) is lost in 100% of these SCLC transformed cases, but rarely in those that remain NSCLC.”
    • Also stated in: § RB is universally lost in resistant SCLC patients · plain
      “IHC analyses were completed on ten resistant EGFR mutant SCLC samples and revealed complete loss of RB expression in all cases”
    • Also stated in: § RB is universally lost in resistant SCLC patients · plain
      “As a control, RB IHC was performed on the 11 resistant tumours that remained NSCLC. RB expression was intact in all but one sample.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    SCLC transformed EGFR mutant cells were highly sensitive to single-agent ABT-263 and markedly more sensitive than EGFR-TKI-resistant NSCLC cell lines harbouring the T790M resistance mutation.

    “SCLC transformed EGFR mutant cells were highly sensitive to single-agent ABT-263 and markedly more sensitive than EGFR-TKI-resistant NSCLC cell lines harbouring the T790M resistance mutation”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In the liver SCLC tumour, there was a relatively large deletion in one copy of RB1 encompassing the entire gene and surrounding region, accompanied by a focal deletion in the second copy spanning only the middle exons of RB1.

    “there was a relatively large deletion in one copy of RB1 that encompassed the entire gene and the surrounding region. This was accompanied by a focal deletion in the second copy that spanned only the middle exons of RB1 but spared the beginning and end of the gene”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    The expression pattern of both the MGH131-1 and MGH131-2 cell lines more closely resembled classical SCLCs with respect to ten microRNAs.

    “The expression pattern of both the MGH131-1 and MGH131-2 cell lines more closely resembled classical SCLCs”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Both SCLC transformed samples had loss of heterozygosity and an inactivating mutation of TP53.

    “as well as loss of heterozygosity and an inactivating mutation of TP53, which is universally altered in classical SCLC2425”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [2425]

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    Two erlotinib-resistant cell lines (MGH125 and MGH141), a resistant patient sample (Patient #10) and two out of four pre-treatment adenocarcinoma samples from patients whose cancers transformed to SCLC (Patients #2 and #6) were negative for RB.

    “two erlotinib-resistant cell lines (MGH125 and MGH141), a resistant patient sample (Patient #10) and two out of four pre-treatment adenocarcinoma samples from patients whose cancers transformed to SCLC (Patients #2 and #6), were also negative for RB.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingnone given

    No detectable 827 tumours were visible after 4 months and treatments were discontinued.

    “No detectable 827 tumours were visible after 4 months and treatments were discontinued.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    RB is invariably lost in classical SCLC.

    “RB is invariably lost in classical SCLC242526.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites 242526

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    SCLC transformed EGFR mutant cancers lose expression of EGFR, as is typical of classical SCLC, and thus are no longer sensitive to EGFR inhibition.

    “These data suggest that SCLC transformed EGFR mutant cancers lose expression of EGFR, as is typical of classical SCLC, and thus it is not surprising that they are no longer sensitive to EGFR inhibition.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Tyrosine kinase inhibitors are effective treatments for non-small-cell lung cancers with epidermal growth factor receptor mutations.

    “Tyrosine kinase inhibitors are effective treatments for non-small-cell lung cancers (NSCLCs) with epidermal growth factor receptor (EGFR) mutations.”
    • Also stated in: § Abstract · plain
      “The tyrosine kinase inhibitors (TKIs) gefitinib, erlotinib and afatinib are effective therapies for non-small-cell lung cancers (NSCLCs) harbouring activating mutations in the epidermal growth factor receptor (EGFR).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites 12345

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    The SCLC transformed tumours harboured the original activating EGFR mutation, suggesting direct evolution from the initial cancer rather than a distinct second primary cancer.

    “Importantly, the tumours that transformed to SCLC harboured the original activating EGFR mutation, suggesting direct evolution from the initial cancer, rather than a distinct, second primary cancer.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [7] Sequist, L. V. et al. Genotypic and histological evolution of lung cancers acquiring resistance to EGFR inhibitors. Sci. Transl. Med. 3, 75ra26 (2011) . source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Premisenone given

    The molecular details underlying the histological change to SCLC and resistance to EGFR TKI therapy, as well as the relatedness of EGFR mutant SCLC to classical SCLC, remain unclear.

    “However, the molecular details underlying this histological change and resistance to EGFR TKI therapy, as well as the relatedness of EGFR mutant SCLC to classical SCLC, remain unclear.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    The two SCLC resistant lesions are more closely related and likely diverged later in the evolution of the resistant disease compared with the adenocarcinoma lesion.

    “This suggests that the two SCLC resistant lesions are more closely related and likely diverged later in the evolution of the resistant disease compared with the adenocarcinoma lesion.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Study design and conductown data

    Control experiments confirmed the robustness of the IHC assay, accurately detecting strong expression in RB-positive tumours, weak RB expression in tumours with reduced levels mediated by shRNA knockdown, and absence of RB in tumours with dual copy loss.

    “Control experiments confirmed the robustness of the IHC assay. For example, it accurately detected strong expression in RB-positive tumours, weak RB expression in tumours with reduced levels mediated by short hairpin RNA (shRNA) knockdown and an absence of RB in tumours with dual copy loss”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductnone given

    A patient-derived model was considered complete when it was independent of the feeder system, free of stromal cells, and determined to maintain known patient tumour mutations.

    “The development of a model was considered complete when it was independent of the feeder system, free of stromal cells and determined to maintain known patient tumour mutations.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Cell lines derived from cancers that either have transformed into SCLC or derived from tumours prone to transform into SCLC both demonstrated genetic loss of RB1.

    “Thus, cell lines derived from cancers that either have transformed into SCLC or derived from tumours prone to transform into SCLC both demonstrated genetic loss of RB1.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    RB knockdown experiments in EGFR mutant cell lines suggest that RB loss was insufficient to cause resistance or induce NE differentiation.

    “Interestingly, RB knockdown experiments in EGFR mutant cell lines suggest that RB loss was insufficient to cause resistance or induce NE differentiation.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Repeat biopsy studies have consistently suggested that SCLC transformed cancers represent an evolution from the initial adenocarcinomas rather than a second coincident cancer, because the activating driver EGFR mutations are identical to the original adenocarcinomas in all cases.

    “However, repeat biopsy studies have consistently suggested that the SCLC transformed cancers represent an evolution from the initial adenocarcinomas rather than a second coincident cancer, because the activating driver EGFR mutations are identical to the original adenocarcinomas in all cases.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [7] Sequist, L. V. et al. Genotypic and histological evolution of lung cancers acquiring resistance to EGFR inhibitors. Sci. Transl. Med. 3, 75ra26 (2011) . source

      Not checked in the free run.

    • cites [13] Yu, H. A. et al. Analysis of tumor specimens at the time of acquired resistance to EGFR-TKI therapy in 155 patients with EGFR-mutant lung cancers. Clin. Cancer Res. 19, 2240–2247 (2013) . source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    Cell viability assays were carried out in a 96-well format with at least four replicates per condition.

    “Cell viability assays were carried out in a 96-well format with at least four replicates per condition.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Study design and conductown data

    RB knockdown was confirmed by western blot analysis.

    “RB knockdown was confirmed by western blot analysis.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationnone given

    We cannot rule out that EGFR mutant SCLC pre-existed before treatment with the EGFR TKI.

    “We cannot rule out that EGFR mutant SCLC pre-existed before treatment with the EGFR TKI.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Study design and conductnone given

    In all cases, resistant cells were grown in the presence of gefitinib to maintain their resistant phenotype.

    “In all cases, resistant cells were grown in the presence of gefitinib to maintain their resistant phenotype.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    EGFR mutant lung cancers that transform to SCLC invariably lose RB expression, similar to classical SCLC.

    “Thus, EGFR mutant lung cancers that transform to SCLC invariably lose RB expression, similar to classical SCLC.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Loss of RB is likely necessary for acquired resistance via transformation to SCLC to develop, but it is not sufficient on its own to promote it.

    “These results suggest that loss of RB is likely necessary in order for acquired resistance via transformation to SCLC to develop, but it is not sufficient on its own to promote it.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Classical SCLC normally do not express EGFR or rely on its activity for growth and survival.

    “which normally do not express EGFR or rely on its activity for growth and survival29”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [29] Byers, L. A. et al. Proteomic profiling identifies dysregulated pathways in small cell lung cancer and novel therapeutic targets including PARP1. Cancer Discov. 2, 798–811 (2012) . source

      Not checked in the free run.

26 of 26

  • The paper relies on this without support.

    EGFR mutant lung adenocarcinomas can transform to SCLC upon acquisition of resistance to EGFR TKI.

    “EGFR mutant lung adenocarcinomas that transform to SCLC upon acquisition of resistance to EGFR TKI”
1 of 1

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Related

Authors
Niederst, M. J., Sequist, L. V., Poirier, J. T., Mermel, C. H., Lockerman, E. L., Garcia, A. R., Katayama, R., Costa, C., Ross, K. N., Moran, T., Howe, E., Fulton, L. E., Mulvey, H. E., Bernardo, L. A., Mohamoud, F., Miyoshi, N., VanderLaan, P. A., Costa, D. B., Jänne, P. A., Borger, D. R., Ramaswamy, S., Shioda, T., Iafrate, A. J., Getz, G., Rudin, C. M., Mino-Kenudson, M., & Engelman, J. A.
Affiliations
  • Harvard University (US)
  • Memorial Sloan Kettering Cancer Center (US)
  • Broad Institute (US)
  • Beth Israel Deaconess Medical Center (US)
Corresponding author
Engelman, Jeffrey A.
ORCID
Venue
Nature Communications
Publisher
Springer Science and Business Media LLC
Published
2015-03-11
Volume
6
Issue
1
Pages
6377-6377
ISSN
2041-1723 (ISSN-L)
DOI
10.1038/ncomms7377
PMC
PMC4357281
OpenAlex
W1987283660
Semantic Scholar
05842924c20b2bc403a70a29aadd515bbbec2440
Cited by
647
References
39
Citations by year
2026: 39 · 2025: 56 · 2024: 47 · 2023: 65 · 2022: 63 · 2021: 74 · 2020: 55 · 2019: 58 · 2018: 72 · 2017: 64 · 2016: 34 · 2015: 20
FWCI
50.43
Type
journal article
Language
en
Open access
Licence
Locations
  • Nature Communications (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • Digital Access to Scholarship at Harvard (DASH) (Harvard University) (submittedVersion, cc-by)
  • RePEc: Research Papers in Economics (submittedVersion)
Funders
  • U.S. Department of Defense
  • Uniting Against Lung Cancer
  • LUNGevity Foundation
  • Lung Cancer Research Foundation
  • National Institutes of Health
  • Japan Society for the Promotion of Science (25710015)
  • National Cancer Institute (R21CA156000, P50CA090578, P30CA008748, R01CA137008)
  • Congressionally Directed Medical Research Programs
Topics
  • Health Sciences › Medicine › Pulmonary and Respiratory Medicine › Lung Cancer Treatments and Mutations
  • Health Sciences › Medicine › Oncology › Lung Cancer Research Studies
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cancer Research › Cancer Genomics and Diagnostics
Keywords
EGFR mutation, lung adenocarcinoma, small cell lung cancer, histologic transformation, tyrosine kinase inhibitor resistance, neuroendocrine differentiation, BCL-2 inhibition, EGFR expression, relapse
MeSH terms
Erlotinib Hydrochloride, Gefitinib, Adenocarcinoma of Lung, Afatinib, Adenocarcinoma, Aniline Compounds, Antineoplastic Agents, Carcinoma, Non-Small-Cell Lung, Humans, Lung, Lung Neoplasms, Mutation, Quinazolines, Recurrence, Sulfonamides, Signal Transduction, Gene Expression Regulation, Neoplastic, Retinoblastoma Protein, Disease Progression, Drug Resistance, Neoplasm, Proto-Oncogene Proteins c-bcl-2, Cell Line, Tumor, Protein Kinase Inhibitors, bcl-X Protein, Small Cell Lung Carcinoma, ErbB Receptors

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.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-06.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-06.

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