INSM1 expression was significantly increased in neoplastic vs nonneoplastic tissue. Furthermore, among midgut GI-NENs, neoplasms with known metastases showed significantly higher expression than those that had not yet metastasized.

PURPOSE The STK11 gene encodes a serine/threonine protein kinase that regulates cell polarity and functions as a tumor suppressor. Patients with non-small-cell lung cancer (NSCLC) and STK11 mutations often have other co-mutations. We evaluated the impact of KRAS and TP53 co-mutations on outcomes after first-line systemic therapy for patients with metastatic or recurrent NSCLC that harbors STK11 mutations. METHODS We conducted a retrospective review of patients with metastatic NSCLC and STK11 mutations treated at the University of Pennsylvania. STK11 mutations were identified through next-generation sequencing (NGS) in tissue or plasma. Cox proportional hazard models were used to determine the relationship between STK11 co-mutations and survival outcomes. The Kaplan-Meier method was used to estimate overall survival (OS) and progression-free survival (PFS). RESULTS From February 2013 to December 2016, samples from 1,385 patients with NSCLC were analyzed by NGS; of these, 77 patients (6%) harbored an STK11 mutation (n = 56, tissue; n = 21, plasma). Of the 62 patients included, 18 had an STK11 mutation alone, 19 had STK11/KRAS, 18 had STK11/TP53, and seven had STK11/KRAS/TP53. Patients with STK11/KRAS co-mutations had a worse median PFS (2.4 months) compared with STK11 alone (5.1 months; log-rank P = .048), STK11/TP53 (4.3 months; log-rank P = .043), and STK11/KRAS/ TP53 (13 months; log-rank P = .03). Patients with STK11/KRAS co-mutation experienced shorter median OS (7.1 months) compared with STK11 alone (16.1 months; log-rank P < .001), STK11/TP53 (28.3 months; log-rank P < .001), and STK11/KRAS/TP53 (22 months; log-rank P = .025). CONCLUSION Among patients with advanced NSCLC and STK11 mutations treated with first-line systemic therapy, co-mutation with KRAS was associated with significantly worse PFS and OS. By contrast, co-mutation of STK11 with TP53 conferred a better prognosis.

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BackgroundInsm1 is a zinc-finger transcription factor transiently expressed throughout the developing nervous system in late progenitors and nascent neurons. Insm1 is also highly expressed in medulloblastomas and other neuroendocrine tumors.ResultsWe generated mice lacking the Insm1 gene and used them to elucidate its role in neurogenic proliferation of the embryonic olfactory epithelium. We found that deletion of Insm1 results in more apical cells and fewer nascent and mature neurons. In the embryonic olfactory epithelium of Insm1 mutants we detect fewer basal progenitors, which produce neurons, and more apical progenitors, which at this stage produce additional progenitors. Furthermore, in the mutants we detect fewer progenitors expressing NEUROD1, a marker of terminally dividing, neuronogenic (neuron-producing) progenitors (immediate neuronal precursors), and more progenitors expressing ASCL1, a marker of the transit amplifying progenitors that migrate from the apical to the basal edges of the epithelium while dividing to generate the terminal, neuronogenic progenitors. Finally, with timed administration of nucleoside analogs we demonstrate that the Insm1 mutants contain fewer terminally dividing progenitors at embryonic day 12.5.ConclusionsAltogether, these results suggest a role for Insm1 in promoting the transition of progenitors from apical and proliferative to basal, terminal and neuronogenic. This role appears partially conserved with that of its nematode ortholog, egl-46. The similar effects of Insm1 deletion on progenitors of embryonic olfactory epithelium and cortex point to striking parallels in the development of these neuroepithelia, and particularly between the basal progenitors of olfactory epithelium and the subventricular zone progenitors of cortex.

In lung adenocarcinoma, canonical EML4-ALK inversion results in a fusion protein with a constitutively active ALK kinase domain. Evidence of ALK rearrangement occurs in a minority (2-7%) of lung adenocarcinoma, and only ~60% of these patients will respond to targeted ALK inhibition by drugs such as crizotinib and ceritinib. Clinically, targeted anti-ALK therapy is often initiated based on evidence of an ALK genomic rearrangement detected by fluorescence in situ hybridization (FISH) of interphase cells in formalin-fixed, paraffin-embedded tissue sections. At the genomic level, however, ALK rearrangements are heterogeneous, with multiple potential breakpoints in EML4, and alternate fusion partners. Using next-generation sequencing of DNA and RNA together with ALK immunohistochemistry, we comprehensively characterized genomic breakpoints in 33 FISH-positive lung adenocarcinomas. Of these 33 cases, 29 (88%) had detectable DNA level ALK rearrangements involving EML4, KIF5B, or non-canonical partners including ASXL2, ATP6V1B1, PRKAR1A, and SPDYA. A subset of 12 cases had material available for RNA-Seq. Of these, eight of eight (100%) cases with DNA rearrangements showed ALK fusion transcripts from RNA-Seq; three of four cases (75%) without detectable DNA rearrangements were similarly negative by RNA-Seq, and one case was positive by RNA-Seq but negative by DNA next-generation sequencing. By immunohistochemistry, 17 of 19 (89%) tested cases were clearly positive for ALK protein expression; the remaining cases had no detectable DNA level rearrangement or had a non-canonical rearrangement not predicted to form a fusion protein. Survival analysis of patients treated with targeted ALK inhibitors demonstrates a significant difference in mean survival between patients with next-generation sequencing confirmed EML4-ALK rearrangements, and those without (20.6 months vs 5.4 months, P<0.01). Together, these data demonstrate abundant genomic heterogeneity among ALK-rearranged lung adenocarcinoma, which may account for differences in treatment response with targeted ALK inhibitors.