biostudies-literatureLi YPNatural Science Foundation of Beijing MunicipalityNational Natural Science Foundation of Chinapgac162https://www.ebi.ac.uk/biostudies/studies/S-EPMC9802398biostudies-literatureUnknown1(4)Retinoblastoma (Rb) is a type of malignant tumor due to abnormal retinogenesis with biallelic mutations of the <i>RB1</i> gene. Its pathogenesis has been proposed as a "two-mutation hypothesis" by Knudson since 1971; however, there remain some debates on disease onset sufficiency of the biallelic <i>RB1</i> mutations. To obtain straightforward evidence for this hypothesis, we investigated whether two-hit mutations of the <i>RB1</i> gene drive tumorigenesis in patient-induced pluripotent stem cell (hiPSC)-derived human retinal organoids (hROs) and whether single allelic mutation hiPSC-derived hROs exhibit molecular and cellular defects. We generated hiPSCs with a heterozygous germline mutation (<i>RB1^m1/ ^wt</i> ) from a Rb patient. A second-allele <i>RB1</i> gene mutatPNAS nexusSecond hit impels oncogenesis of retinoblastoma in patient-induced pluripotent stem cell-derived retinal organoids: direct evidence for Knudson's theory.PMC980239881970838Z2000148217147082125007Shen RJLi YPZhang XWang YTJin ZBWang WJin LWJin KfalseSecond hit impels oncogenesis of retinoblastoma in patient-induced pluripotent stem cell-derived retinal organoids: direct evidence for Knudson's theory.Retinoblastoma (Rb) is a type of malignant tumor due to abnormal retinogenesis with biallelic mutations of the <i>RB1</i> gene. Its pathogenesis has been proposed as a "two-mutation hypothesis" by Knudson since 1971; however, there remain some debates on disease onset sufficiency of the biallelic <i>RB1</i> mutations. To obtain straightforward evidence for this hypothesis, we investigated whether two-hit mutations of the <i>RB1</i> gene drive tumorigenesis in patient-induced pluripotent stem cell (hiPSC)-derived human retinal organoids (hROs) and whether single allelic mutation hiPSC-derived hROs exhibit molecular and cellular defects. We generated hiPSCs with a heterozygous germline mutation (<i>RB1^m1/ ^wt</i> ) from a Rb patient. A second-allele <i>RB1</i> gene mutat2022-01-01T00:00:00Z2022 Sep2026-07-09T13:22:13.134Z2025-04-06T18:02:50.284ZS-EPMC98023983671483910.1093/pnasnexus/pgac162