The objective of the current study was to evaluate the sensitivity and specificity of INSM1 ICC on direct smears (DS) from patients with SCLC in comparison with IHC on small biopsies (SBs).
Insulinoma-associated protein 1 is a novel diagnostic marker of small cell lung cancer in bronchial brushing and cell block cytology from pleural effusions: Validity and reliability with cutoff value.
Thus, the reciprocal expression of INSM1 and YAP1 appears to stratify SCLC into distinct subgroups and may be useful, along with <i>RB1</i> mutation status, to identify chemo-refractory SCLC patients.
Taken together, our results argue that LSD1 plays an important role in neuroendocrine-associated transcription and cell proliferation of SCLC via interactions with the SNAG domain proteins INSM1 and GFI1B.
Insulinoma associated-1 (INSM1) gene is expressed exclusively in early embryonic neuroendocrine tissues, but has been found highly re-activated in most of the neuroendocrine tumors including small cell lung carcinoma.
Despite this, the INSM1 promoter activity was found to be unchanged or increased in SCLC chemoresistant cells and xenografts compared to chemosensitive variants.
This INSM1 promoter region showed very high levels of expression in most of the SCLC cell lines and expression was absent in cell lines of non-neuroendocrine origin.