Gleditsch Katrina, Peñas Jorge, Mercer Danielle, Umrigar Ayesha, Briscoe James, Stark Matthew, Tsien Fern, Hollenbach Andrew D
Department of Genetics, Louisiana State University Health Sciences Center, New Orleans, LA, United States.
Division of Pediatric Hematology/Oncology, Children's Hospital of New Orleans, New Orleans, LA, United States.
Front Cell Dev Biol. 2020 Sep 18;8:564136. doi: 10.3389/fcell.2020.564136. eCollection 2020.
Alveolar rhabdomyosarcoma (ARMS) is characterized by one of three translocation states: (2;13) (q35;q14) producing PAX3-FOXO1, (1;13) (p36;q14) producing PAX7-FOXO1, or translocation-negative. Tumors with (2;13) are associated with greater disease severity and mortality than (1;13) positive or translocation negative patients. Consistent with this fact, previous work concluded that a molecular analysis of RMS translocation status is essential for the accurate determination of prognosis and diagnosis. However, despite this knowledge, most diagnoses rely on histology and in some cases utilize fluorescence hybridization (FISH) probes unable to differentiate between translocation products. Along these same lines, diagnostic RT-PCR analysis, which can differentiate translocation status, is unable to determine intratumoral translocation heterogeneity, making it difficult to determine if heterogeneity exists and whether correlations exist between this heterogeneity and patient outcomes. Using newly developed FISH probes, we demonstrate that intratumoral heterogeneity exists in ARMS tumors with respect to the presence or absence of the translocation product. We found between 3 and 98% of cells within individual tumor samples contained a translocation event with a significant inverse correlation ( = 0.66, = 0.001) between the extent of intratumoral translocation heterogeneity and failure-free survival of patients. Taken together, these results provide additional support for the inclusion of the molecular analysis of these tumors and expand on this idea to support determining the extent of intratumoral translocation heterogeneity in the diagnosis of ARMS to improve diagnostic and prognostic indicators for patients with these tumors.
肺泡横纹肌肉瘤（ARMS）具有三种易位状态之一：产生PAX3 - FOXO1的（2；13）（q35；q14）、产生PAX7 - FOXO1的（1；13）（p36；q14）或易位阴性。与（1；13）阳性或易位阴性患者相比，具有（2；13）的肿瘤与更高的疾病严重程度和死亡率相关。与此事实一致，先前的研究得出结论，对横纹肌肉瘤易位状态进行分子分析对于准确判断预后和诊断至关重要。然而，尽管有此认识，大多数诊断仍依赖组织学，并且在某些情况下使用无法区分易位产物的荧光原位杂交（FISH）探针。同样，能够区分易位状态的诊断性逆转录聚合酶链反应（RT - PCR）分析无法确定肿瘤内易位异质性，从而难以确定是否存在异质性以及这种异质性与患者预后之间是否存在相关性。使用新开发的FISH探针，我们证明在ARMS肿瘤中，就易位产物的存在与否而言，存在肿瘤内异质性。我们发现，在单个肿瘤样本中，3%至98%的细胞发生了易位事件，肿瘤内易位异质性程度与患者无病生存率之间存在显著负相关（r = - 0.66，P = 0.001）。综上所述，这些结果为纳入这些肿瘤的分子分析提供了额外支持，并扩展了这一观点，以支持在ARMS诊断中确定肿瘤内易位异质性的程度，从而改善这些肿瘤患者的诊断和预后指标。
