RESUMEN
To identify genetic alterations associated with tongue cancer recurrence in young adults, whole exome sequencing of the primary tumor, recurrence, and whole blood samples from young patients with tongue cancer was performed. A frameshift mutation in the TP53 gene was detected in the primary tumor and recurrence tumor tissue. A mutation in the EPHB6 gene was detected in the recurrence and was absent in the primary tumor. In addition, the primary tumor and recurrence tongue cancer tissue harbored amplification of the 20p13 region containing C20orf96, DEFB125, DEFB126, DEFB127, DEFB128, DEFB129, DEFB132, and ZCCHC3 genes. Thus, genetic alterations have been identified that are associated with tongue cancer recurrence in young adults.
Asunto(s)
Secuenciación del Exoma , Recurrencia Local de Neoplasia , Neoplasias de la Lengua , Proteína p53 Supresora de Tumor , Humanos , Neoplasias de la Lengua/genética , Neoplasias de la Lengua/patología , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patología , Proteína p53 Supresora de Tumor/genética , Adulto Joven , Masculino , Adulto , Femenino , Mutación del Sistema de Lectura/genéticaRESUMEN
Juvenile myelomonocytic leukemia (JMML) is a rare myeloproliferative disease of early childhood that develops due to mutations in the genes of the RAS-signaling pathway. Next-generation high throughput sequencing (NGS) enables identification of various secondary molecular genetic events that can facilitate JMML progression and transformation into secondary acute myeloid leukemia (sAML). The methods of single-cell DNA sequencing (scDNA-seq) enable overcoming limitations of bulk NGS and exploring genetic heterogeneity at the level of individual cells, which can help in a better understanding of the mechanisms leading to JMML progression and provide an opportunity to evaluate the response of leukemia to therapy. In the present work, we applied a two-step droplet microfluidics approach to detect DNA alterations among thousands of single cells and to analyze clonal dynamics in two JMML patients with sAML transformation before and after hematopoietic stem cell transplantation (HSCT). At the time of diagnosis both of our patients harbored only "canonical" mutations in the RAS signaling pathway genes detected by targeted DNA sequencing. Analysis of samples from the time of transformation JMML to sAML revealed additional genetic events that are potential drivers for disease progression in both patients. ScDNA-seq was able to measure of chimerism level and detect a residual tumor clone in the second patient after HSCT (sensitivity of less than 0.1% tumor cells). The data obtained demonstrate the value of scDNA-seq to assess the clonal evolution of JMML to sAML, response to therapy and engraftment monitoring.