Elucidation of a new therapeutic mechanism for small cell lung cancer: A new therapeutic concept to rewrite the proliferation program of cancer cells
Chiba University and Taiho Pharmaceutical discovered that the compound TAS1440 effectively suppresses small cell lung cancer cell growth by inhibiting LSD1 and altering transcriptional networks. Published in Nature Communications.
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- 📰 Published: April 10, 2026 at 01:00
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- 🤖 AI Analyzed: April 19, 2026 at 23:50 (215h 20m after Collected)
Professor Tomoaki Tanaka and Researcher Hidehiro Miya from the Graduate School of Medicine, Chiba University, along with a research team from Taiho Pharmaceutical Co., Ltd., investigated the molecular mechanisms related to the proliferation and survival of small cell lung cancer (SCLC) (Note 1). As a result, they revealed the molecular mechanism by which "TAS1440", a compound that inhibits the function of a protein called LSD1 (lysine-specific histone demethylase 1) (Note 2), significantly alters the molecular network and suppresses cancer cell proliferation by inhibiting the interaction between LSD1 and the transcription factor INSM1 (Note 3), which is particularly important in neuroendocrine-type SCLC.
This research finding was published in the British scientific journal Nature Communications on March 25, 2026.
(Link to the paper: 10.1038/s41467-026-70984-1)
■ Research Background
SCLC progresses extremely quickly among lung cancers and has a high recurrence rate, making it one of the most difficult cancers to treat even today. Recent studies have revealed that SCLC can be classified into multiple molecular subtypes based on characteristics of gene expression, and the properties of cancer cells are maintained by different molecular mechanisms in each subtype. However, effective treatments targeting these molecular mechanisms have not yet been established.
■ Key Points of the Research Results (For details, please refer to the appendix)
1. Elucidation of the relationship between SCLC molecular subtypes and drug sensitivity
As a result of classifying 22 SCLC cell lines into 4 molecular subtypes and evaluating their sensitivity to TAS1440, it became clear that TAS1440 shows a particularly strong proliferation-suppressing effect in the SCLC-A subtype.
2. Discovery of the dissociation of the INSM1–SMAD2–LSD1 transcriptional repressor complex
In SCLC-A cells, it was found that transcription factors INSM1 and SMAD2 (Note 4) form a complex with LSD1 to regulate the expression of genes involved in cancer cell proliferation. It was revealed that TAS1440 dissociates this transcriptional repressor complex in addition to inhibiting the enzymatic activity of LSD1.
3. Activation of tumor suppressor signaling pathways (TGF-β (Note 5) and NOTCH (Note 6))
It was found that when INSM1 and SMAD2 are dissociated from the LSD1 complex by TAS1440, the chromatin structure changes, activating the TGF-β and NOTCH signaling pathways. This indicated that a transcriptional program suppressing the proliferation of cancer cells is induced.
4. Demonstration of INSM1-dependent antitumor effects
In cells where INSM1 was deleted, the antitumor effect of TAS1440, which is exerted through an INSM1-dependent molecular mechanism, was significantly diminished, resulting in a marked reduction in its proliferation-suppressing effect.
5. Therapeutic effect of TAS1440 in mouse models
In mouse models transplanted with SCLC-A cells, oral administration of TAS1440 showed an antitumor effect that significantly suppressed tumor growth.
■ Future Outlook
This research highlights gene expression regulation in SCLC
This research finding was published in the British scientific journal Nature Communications on March 25, 2026.
(Link to the paper: 10.1038/s41467-026-70984-1)
■ Research Background
SCLC progresses extremely quickly among lung cancers and has a high recurrence rate, making it one of the most difficult cancers to treat even today. Recent studies have revealed that SCLC can be classified into multiple molecular subtypes based on characteristics of gene expression, and the properties of cancer cells are maintained by different molecular mechanisms in each subtype. However, effective treatments targeting these molecular mechanisms have not yet been established.
■ Key Points of the Research Results (For details, please refer to the appendix)
1. Elucidation of the relationship between SCLC molecular subtypes and drug sensitivity
As a result of classifying 22 SCLC cell lines into 4 molecular subtypes and evaluating their sensitivity to TAS1440, it became clear that TAS1440 shows a particularly strong proliferation-suppressing effect in the SCLC-A subtype.
2. Discovery of the dissociation of the INSM1–SMAD2–LSD1 transcriptional repressor complex
In SCLC-A cells, it was found that transcription factors INSM1 and SMAD2 (Note 4) form a complex with LSD1 to regulate the expression of genes involved in cancer cell proliferation. It was revealed that TAS1440 dissociates this transcriptional repressor complex in addition to inhibiting the enzymatic activity of LSD1.
3. Activation of tumor suppressor signaling pathways (TGF-β (Note 5) and NOTCH (Note 6))
It was found that when INSM1 and SMAD2 are dissociated from the LSD1 complex by TAS1440, the chromatin structure changes, activating the TGF-β and NOTCH signaling pathways. This indicated that a transcriptional program suppressing the proliferation of cancer cells is induced.
4. Demonstration of INSM1-dependent antitumor effects
In cells where INSM1 was deleted, the antitumor effect of TAS1440, which is exerted through an INSM1-dependent molecular mechanism, was significantly diminished, resulting in a marked reduction in its proliferation-suppressing effect.
5. Therapeutic effect of TAS1440 in mouse models
In mouse models transplanted with SCLC-A cells, oral administration of TAS1440 showed an antitumor effect that significantly suppressed tumor growth.
■ Future Outlook
This research highlights gene expression regulation in SCLC