Fig. 6: Loss of LAPTM4B accelerates ferroptosis-mediated suppression of tumor growth in vivo. | Cell Death & Disease

Fig. 6: Loss of LAPTM4B accelerates ferroptosis-mediated suppression of tumor growth in vivo.

From: LAPTM4B counteracts ferroptosis via suppressing the ubiquitin-proteasome degradation of SLC7A11 in non-small cell lung cancer

Fig. 6

A Flowchart depicting the experimental design of the nude mice xenograft study. Female nude mice were injected with 6 × 106 WT or LAPTM4B KO A549 cells into the flanks. Once viable tumors had formed after 24 days, the mice were randomly divided into two subgroups, and administered 25 mg/kg/day of erastin or vesicle via intraperitoneal injections. The mice were sacrificed after 12 days of treatment. B Photographs of the mice at the time of sacrifice. C Photographs of the tumors used for further analysis. Note: Tumors exhibiting the highest and lowest weights within each experimental group were excluded from further analyses, due to the observed variability in tumor size. D Relative tumor weight in the mice with different treatments. Data presented as mean ± SEM, normalized to “WT_DMSO”. p(WT_DMSO, KO_DMSO) = 0.0215, p(KO_DMSO, KO_Erastin) = 0.027, p(WT_Erastin, KO_Erastin) = 0.0017. E Mouse weight (grams) at the time of sacrifice. F Immunohistochemistry (IHC) staining of Ki67, LAPTM4B, and SLC7A11 in mouse tumor tissue samples. Left panel: representative images from H&E staining and IHC staining. Scale bar: 100 µm. Right panel: quantification of IHC results. Data from 26 images from at least 4 mice per group. Data presented as mean ± SEM, normalized to “WT_DMSO”. Statistical analysis revealed the following p-values: For Ki67 staining, p(WT_DMSO, WT_Erastin)=0.0004, p(WT_DMSO, KO_DMSO) = 0.0005, p(WT_DMSO, KO_Erastin) = 4.35E−05, p(WT_Erastin, KO_Erastin) = 4.716E−05, p(KO_DMSO, KO_Erastin) = 0.0018. For LAPTM4B staining, p(WT_DMSO, WT_Erastin) = 0.0324, p(WT_DMSO, KO_DMSO) = 0.0001, p(WT_Erastin, KO_Erastin) = 4.924E−07, p(WT_DMSO, KO_Erastin) = 2.16E−07. For SLC7A11 staining, p(WT_DMSO, KO_DMSO) = 0.0009, p(WT_Erastin, KO_Erastin) = 0.0005. G Western blotting analysis of LAPTM4B, SLC7A11, and GPX4 protein levels in mouse tumor tissue samples. Representative experiments shown. H Quantification of Western blotting results from (G). Statistical analysis revealed the following p values: For LAPTM4B, p(WT_DMSO, KO_DMSO) = 0.0001, p(WT_DMSO, KO_Erastin) = 0.0001, p(WT_Erastin, KO_Erastin) = 0.0058. For SLC7A11, p(WT_DMSO, KO_DMSO) = 0.0052, p(WT_DMSO, KO_ Erastin) = 0.0309, p(KO_DMSO, KO_Erastin) = 0.0156, p(WT_Erastin, KO_Erastin) = 0.0156. I Correlation between expression levels of LAPTM4B and SLC7A11 (Left Panel) in mouse tumor samples (R = 0.4774, p = 0.0092), and correlation between expression levels of LAPTM4B and GPX4 (Right Panel, R = −0.1635, p = 0.2226). J Measurement of malondialdehyde (MDA) in tumor samples from mice with different treatments. Data from 15 tissues from at least 4 mice per group. Quantification of n = 3 experiments, presented as mean ± SEM, normalized to “WT_DMSO”. Statistical analysis revealed the following p values: p(WT_DMSO, WT_Erastin)=0.0066, p(WT_DMSO, KO_DMSO) = 0.033, p(WT_Erastin, KO_Erastin)=0.0034, p(KO_DMSO, KO_Erastin) = 0.0029.

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