Fig. 6: Chemotherapy alters gene expression in viable child ovarian follicles of good morphology.

Since some child patients had received first-line chemotherapy prior to fertility preservation, the potential effects of the cumulative dose of alkylating chemotherapy (CED, cyclophosphamide equivalent dose) on follicle gene expression were examined. A Principal component analysis displayed the expected division of follicles by developmental stage across PC1, while PC2 distributed the follicles by the level of chemotherapy treatment. B When comparing gene expression between patients at low risk of gonadal damage (CED 0–3000 g/m²) to those at high risk (CED ≥6000 g/m²), 166 differentially expressed genes were identified with significant enrichment of pathways related to interferon signaling. C Expression of selected interferon signaling pathway genes correlated with CED exposure levels based on Spearman coefficients (CED 0 n = 10; CED 3000 n = 5; CED 5952 n = 3; CED 6000 n = 6; and CED 8328 n = 12). In box plots, the center line represents the median, the hinges correspond to the first and third quartiles (interquartile range), and the whiskers extend to 1.5 times the interquartile range from the hinges. D Immunofluorescence staining for IFI44L in an independent set of samples (untreated, 6 years old, CED = 0; treated, 6 years old, CED = 4200 g/m²) confirmed upregulation in follicles at the protein level. E The circle plot illustrating follicle-to-follicle communication based on secreted signals reveals that the communication strength of Group 2 follicles is comparable under both low and high CED exposure. The line thickness indicates the strength of the communication, color specifies the group, and the size of the dots relates to the number of follicles in each group. Box plots display the median, interquartile range, and minimum and maximum (whiskers) values of the normalized count. Source data are provided as a Source Data file.