Journal: Cell Reports
Article Title: Functional characterization of the ATOH1 molecular subtype indicates a pro-metastatic role in small cell lung cancer
doi: 10.1016/j.celrep.2025.115603
Figure Lengend Snippet: ATOH1 depletion decreases tumor growth kinetics and metastasis in vivo (A) In vivo study design to investigate subcutaneous (s.c.) tumor growth and metastasis after s.c. tumor resection. CDX17P ShRen and ShATOH1#3 (ShATOH1) were injected s.c. into NSG mice and left for 19 days for tumor establishment. Mice were then fed either a standard diet (control arms, n = 3) or DOX-supplemented food (experimental arms, n = 15), and s.c. tumor growth was assessed. Tumors were surgically resected when at 500–800 mm 3 to allow for metastatic dissemination. Mice were kept on the study for 28 days or until s.c. tumors reached maximum size, whichever came first. (B) Tumor growth curves from day of first tumor measurement to s.c. tumor resection for mice implanted with ShRen and ShATOH1 cells and fed a DOX-supplemented diet. Black, ShRen fed a DOX diet; red, ShATOH1#3 fed a DOX diet. 15 mice per cohort; data reported as mean ± SD. Dotted lines indicate when tumors from each cohort reached 500 mm 3 : ShRen, 14 ± 3 days; ShATOH1, 21 ± 5 days. (C) Quantification of tumor growth curves slopes in (B). Shades of gray, control cohort fed a standard diet for study duration. p values were calculated with ANOVA test, and slope of the curve is reported as mean ± SD per cohort. (D) Kaplan-Meier curve of time to surgical resection of s.c. tumor or maximum 800 mm 3 for inoperable tumors. Control arms, fed a standard diet, are reported in scales of gray. p values were calculated with log rank Mantel-Cox test. (E) Quantification of metastatic dissemination to the liver in 3 mice fed a standard diet, 5 Sh Ren and 15 Sh ATOH1 tumor-bearing mice fed a DOX diet underwent surgical resection of s.c. tumors and survived on the study thereafter for at least 22 days. Data are shown as percentage of animals displaying metastatic dissemination (disseminated tumor cells and micro/macro-metastases, red) or no metastatic dissemination in the liver (blue). Metastases were identified by human mitochondrion staining. (F) Representative images of human mitochondria, GFP and ATOH1 IHC staining in liver from Sh Ren DOX-fed and Sh ATOH1#3 DOX-fed cohorts. Scale bars: 200 μm for human mitochondria and GFP; 100 μm for ATOH1. (G and H) Quantification of GFP (G) and ATOH1 (H) IHC staining in metastases from 2 DOX-untreated ShRen, 3 DOX-untreated ShATOH1#3, 4 ShRen DOX-fed, and 6 ShATOH1#3 DOX-fed mice. Data are geometric mean ± geometric SD. p values are reported as per two-tailed unpaired Mann Whitney U test. (I) In vivo study design to investigate development of metastasis following intracardiac implantation. Prior to cell implantation, ATOH1 depletion was DOX induced for 4 days in vitro , followed by sorting GFP+, viable cells by flow cytometry. Untreated control cells were sorted exclusively for viable cells. Animals in DOX-treated cohorts were fed a DOX-supplemented diet 24 h before implantation and kept on that diet until the endpoint. Animals in the uninduced control groups were given a standard diet. Animals from all 4 cohorts (ShRen with or without DOX and ShATOH1 with or without DOX) were removed at onset of symptoms (i.e., distended abdomen; detailed in STAR Methods) or after 70 days. (J) Kaplan-Meier curve of time to sacrifice. Control cohorts, fed a standard diet, are reported in scales of gray. p values were calculated with log rank Mantel-Cox test. (K) Quantification of metastatic liver dissemination for each cohort. Data are shown as in (D). (L) Quantification of metastatic liver cells per cohort. Metastatic cells were identified based on human mitochondrion staining. Data are shown as mean ± SD. p values were calculated with a two-tailed unpaired Mann Whitney U test. (M and N) Quantification of GFP (M) and ATOH1 (N) IHC staining in metastases from 5 DOX-untreated ShRen, 5 DOX-untreated ShATOH1, 5 ShRen DOX-fed mice, and 1 ShATOH1#3 DOX-fed mouse. Data are shown as geometric mean ± geometric SD. No statistical test could be performed, as ShATOH1 contained only one value.
Article Snippet: PET-28A vector for ATOH1 insertion , Originally from Addgene, now in-house , N/A.
Techniques: In Vivo, Injection, Control, Staining, Immunohistochemistry, Two Tailed Test, MANN-WHITNEY, In Vitro, Flow Cytometry