Fig. 5: SCLC induces neuronal hyperexcitability.
From: Neuronal activity-dependent mechanisms of small cell lung cancer pathogenesis
a, Immunofluorescence of human iPS cell-derived neurons in monoculture (left) or co-cultured with 16T SCLC cells (right). Arrowheads indicate colocalized pre-synaptic (synapsin) and post-synaptic (HOMER1) puncta along neuronal processes (neurofilament (NF)). Scale bar, 25 µm. b, Quantification of data in a (per 10 µm neurofilament length, n = 12 coverslips for neuron baseline and n = 10 coverslips for co-culture, P < 0.0001). c, Representative 500 ms recording of human iPS cell-derived glutamatergic neurons at baseline versus co-cultured with 16T SCLC cells using MEA (n = 6 per condition). d, Representative traces of spike amplitude in human iPS cell-derived glutamatergic neurons at baseline versus co-cultured with 16T SCLC cells. e, Quantification of data in c,d (n = 24 spikes in neuron baseline and n = 168 spikes in co-culture condition, P < 0.0001). f, As in e, but for human H446 SCLC cells (n = 363 spikes in neuron baseline and n = 2,721 spikes in co-culture, P < 0.0001). g, Paradigm for local field recordings in SCLC hippocampal allografts. Created in BioRender. Savchuk, S. (2025) https://BioRender.com/5fwotqm. h, Representative traces of local field potential in response to local stimulation of tumour allografts and control contralateral hippocampus. i, Extracellular local field potential (fEPSP) slope in response to various axonal stimulation intensities in the tumour-infiltrated or control contralateral hippocampus (data fit to a nonlinear regression and compared using the extra-sum-of-squares F-test; n = 24 tumour and n = 25 control across 6 mice, P < 0.0001). j, GSEA of scRNA-seq data from 16T SCLC cells isolated from either monoculture or neuron co-culture (Fig. 2f,g) reveals a distinct cluster that is enriched for astrocyte-related genes. All gene lists in Supplementary Table 1. k, Quantification of ssGSEA scores for astrocyte-related genes across the 16 identified clusters detects upregulation of astrocyte signature in cluster 5 (highlighted in red). Statistical testing in Supplementary Table 2. l, Expression of astrocyte synaptogenesis-related genes in cells isolated from patient lung primary, recurrent or non-brain-metastatic lesions45 (n = 16) versus patient SCLC brain metastases (n = 12, P < 0.0001). m, Representative immunofluorescence of human H446 SCLC (GFP) xenografted in cortex of mice treated with vehicle or levetiracetam (LEV). Proliferating cells are labelled with Ki67. Scale bars, 50 µm. n, Quantification of data in m (n = 3 vehicle and n = 5 levetiracetam-treated mice, P = 0.0065). o, As in n, but for mouse 16T SCLC cells (n = 6 vehicle and n = 7 levetiracetam-treated mice, P < 0.0001). Data are mean ± s.e.m. (b,i,n,o); violin plot (e,f,k); and violin and box plot (l). Unpaired t-test (b,n,o); Mann–Whitney test (e,f); one-way ANOVA with Tukey correction (k); pairwise Wilcoxon rank sum test (l). All tests are two-tailed.
