RESUMO
Patients with advanced/recurrent mucoepidermoid carcinoma (MEC) have a poor prognosis. This study aimed to establish and characterize human mucoepidermoid carcinoma cell lines from the initial surgical specimen and biopsy specimen upon recurrence from the same patient to provide a resource for MEC research. MEC specimens from the initial surgical procedure and biopsy upon recurrence were used to establish cell lines. The established cell lines were cytogenetically characterized using multi-color fluorescence in situ hybridization and detection, and the sequence of the CRTC1-MAML2 chimeric gene was determined. Furthermore, the susceptibility of head and neck mucoepidermoid carcinoma to standard treatment drugs such as cisplatin, 5-fluorouracil, and cetuximab was investigated. We successfully established unique MEC cell lines, AMU-MEC1, from an initial surgical specimen and AMU-MEC1-R1 and AMU-MEC1-R2 from the recurrent biopsy specimen in the same patient. These cell lines exhibited epithelial morphology and developed in vitro-like cobblestones. They shared eight chromosomal abnormalities, including der(19)ins(19;11)(p13;?), which resulted in a chimeric CRTC1-MAML2 gene, indicating the same origin of the cell lines. The susceptibility of all cell lines to cisplatin and 5-fluorouracil was low. Interestingly, EGFR dependency for cell growth decreased in AMU-MEC-R1 and AMU-MEC-R2 but was retained in AMU-MEC1. These cytogenetic and biochemical findings suggest that the established cell lines can be used to investigate the disease progression mechanisms and develop novel therapeutics for MEC.
Assuntos
Carcinoma Mucoepidermoide , Neoplasias das Glândulas Salivares , Humanos , Proteínas de Ligação a DNA/genética , Transativadores/genética , Carcinoma Mucoepidermoide/patologia , Hibridização in Situ Fluorescente , Cisplatino , Fatores de Transcrição/genética , Biópsia , Linhagem Celular Tumoral , Fluoruracila/farmacologia , Neoplasias das Glândulas Salivares/patologia , Proteínas de Fusão Oncogênica/genéticaRESUMO
Multiple myeloma (MM) cells are derived from mature B cells based on immunoglobulin heavy chain (IgH) gene analysis. The onset of MM is often caused by a reciprocal chromosomal translocation (cTr) between chr 14 with IgH and chr 11 with CCND1. We propose that mature B cells gain potential to transform by reprograming, and then chromosomal aberrations cause the development of abnormal B cells as a myeloma-initiating cell during B cell redifferentiation. To study myeloma-initiating cells, we have already established normal B cell-derived induced pluripotent stem cells (BiPSCs). Here we established two BiPSCs with reciprocal cTr t(11;14) using the CRISPR/Cas9 system; the cleavage site were located in the IgH Eµ region of either the VDJ rearranged allele or non-rearranged allele of IgH and the 5'-upsteam region of the CCND1 (two types of BiPSC13 with t(11;14) and MIB2-6 with t(11;14)). Furthermore, p53 was deleted using the CRISPR/Cas9 system in BiPSC13 with t(11;14). These BiPSCs differentiated into hematopoietic progenitor cells (HPCs). However, unlike cord blood, those HPCs did not differentiated into B lymphocytes by co-culture with BM stromal cell. Therefore, further ingenuity is required to differentiate those BiPSCs-derived HPCs into B lymphocytes.
Assuntos
Ciclina D1/genética , Cadeias Pesadas de Imunoglobulinas/genética , Mieloma Múltiplo/genética , Proteína Supressora de Tumor p53/genética , Linfócitos B/metabolismo , Linfócitos B/patologia , Sistemas CRISPR-Cas/genética , Diferenciação Celular/genética , Linhagem Celular Tumoral , Aberrações Cromossômicas , Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 14/genética , Células-Tronco Hematopoéticas , Humanos , Hibridização in Situ Fluorescente , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Translocação Genética/genética , Éxons VDJ/genéticaRESUMO
The recently described ST7 (for suppression of tumorigenicity 7) gene has been suggested to be a major target gene on chromosome 7q31 for inactivation in a variety of human neoplasias. Loss of heterozygosity (LOH) in chromosome 7q31 is frequently observed in a variety of human neoplasias including malignant myeloid tumors. We, therefore, sought to examine a total of 22 human malignant myeloid tumor cell lines comprising 17 of acute myelogenous leukemia (AML) cell lines and 5 chronic myelogenous leukemia (CML) cell lines for somatic mutations of the ST7 gene by means of bidirectional direct DNA sequencing analysis. As a result, no mutations were detected in any of these cell lines examined. In addition, our analysis of two breast tumor cell lines, which had been reported to harbour ST7 mutations, provided no evidence for such mutations. Thus, our results strongly suggest that somatic mutations of ST7 do not commonly contribute to the molecular pathogenesis of human malignant myeloid tumors and further raise questions regarding the pathological role of ST7 as a tumor suppressor gene (TSG) in a variety of human neoplasias.