Primary Cilia Are Frequently Present in Small Cell Lung Carcinomas but Not in Non-Small Cell Lung Carcinomas or Lung Carcinoids

Kazuya Shinmura, Hisami Kato, Hideya Kawasaki, Takahiko Hariyama, Kimio Yoshimura, Kazuo Tsuchiya, Hirofumi Watanabe, Isao Ohta, Eri Asahina, Fumiya Sumiyoshi, Keisuke Hamada, Yuichi Kawanishi, Akikazu Kawase, Kazuhito Funai, Haruhiko Sugimura

Research output: Contribution to journalArticlepeer-review


Most human malignant neoplasms show loss of primary cilia (PC). However, PC are known to be retained and involved in tumorigenesis in some types of neoplasms. The PC status in lung carcinomas remains largely uninvestigated. In this study, we comprehensively assessed the PC status in lung carcinomas. A total of 492 lung carcinomas, consisting of adenocarcinomas (ACs) (n = 319), squamous cell carcinomas (SCCs) (n = 152), and small cell lung carcinomas (SCLCs) (n = 21), were examined by immunohistochemical analysis using an antibody against ARL13B, a marker of PC. The PC-positive rate was markedly higher in SCLCs (81.0%) than in ACs (1.6%) and SCCs (7.9%). We subsequently performed analyses to characterize the PC-positive lung carcinomas further. PC-positive lung carcinomas were more numerous and had longer PC than normal cells. The presence of PC in these cells was not associated with the phase of the cell cycle. We also found that the PC were retained even in metastases from PC-positive lung carcinomas. Furthermore, the hedgehog signaling pathway was activated in PC-positive lung carcinomas. Because ARL13B immunohistochemistry of lung carcinoids (n = 10) also showed a statistically significantly lower rate (10.0%) of PC positivity than SCLCs, we searched for a gene(s) that might be upregulated in PC-positive SCLCs compared with lung carcinoids, but not in PC-negative carcinomas. This search, and further cell culture experiments, identified HYLS1 as a gene possessing the ability to regulate ciliogenesis in PC-positive lung carcinomas. In conclusion, our findings indicate that PC are frequently present in SCLCs but not in non-SCLCs (ACs and SCCs) or lung carcinoids, and their PC exhibit various specific pathobiological characteristics. This suggests an important link between lung carcinogenesis and PC.

Original languageEnglish
Pages (from-to)100007
Number of pages1
JournalLaboratory investigation; a journal of technical methods and pathology
Issue number2
Publication statusPublished - 2023 Feb 1


  • HYLS1
  • hedgehog signaling pathway
  • lung carcinoid
  • non-small cell lung carcinoma
  • primary cilia
  • small cell lung carcinoma

ASJC Scopus subject areas

  • General Medicine


Dive into the research topics of 'Primary Cilia Are Frequently Present in Small Cell Lung Carcinomas but Not in Non-Small Cell Lung Carcinomas or Lung Carcinoids'. Together they form a unique fingerprint.

Cite this