DKC1 affects proliferation, apoptosis and cell cycle of mucosal melanoma cells relating to MEK-ERK pathway / 中国肿瘤生物治疗杂志

@#[Abstract] Objective: To investigate the effects of dyskerin pseudouridine synthase 1 (DKC1) on the proliferation, cell cycle and apoptosis of mucosal melanoma cells and its potential mechanisms. Methods: qPCR was used to detect the mRNA expression of DKC1 in mucosal melanoma cell lines HMV II, GAK and normal skin cell line BJ. HMV II and GAK cells were interfered with DKC1 siRNA (si-DKC1 group) and control siRNA(si-Ctrl group) respectively; 48 h later, qPCR and Western blotting were used to verify the interfer‐ence efficiency. CCK-8 assay was used to detect the effect of DKC1 knockdown on the proliferation of mucousal melanoma cells. Flow cytometry was used to detect the apoptosis and cell cycles. Western blotting and qPCR were used to detect the molecule expressions of related pathways. Results: The mRNA and protein expression levels of DKC1 in HMV II and GAK cells were significantly higher than those in BJ cells (all P<0.01). After 48 h of siRNA transfection, compared with the si-Ctrl group, the mRNA and protein levels of DKC1 in HMV II and GAK cells of the si-DKC1 group significantly reduced (all P<0.01), the cell proliferation level significantly re‐duced (P<0.05 or P<0.01), and the apoptosis rate of cells significantly increased (all P<0.01); in addition, the mRNA expressions of proapoptotic molecules caspase 9, BAK and PUMA increased significantly (P<0.05 or P<0.01) and the cell cycle was blocked (P<0.05 or P<0.01); moreover, the phosphorylation levels of MEK and ERK1/2 were significantly reduced (P<0.05). Conclusion: Knockdown of DKC1 can inhibit the proliferation of mucousal melanoma cells, promote cell cycle arrest and induce apoptosis, and its mechanism may be related to MEK/ERK signal pathway.

Identification of DKC1 gene mutation in an indian patient.

Dyskeratosis congenita - X-linked variety was diagnosed in a twelve year old male child with cutaneous pigmentary changes and dystrophic changes in nails of hands and feet. His elder brother had similar nail changes and had died at twelve yr of age. We demonstrated the A353V mutation in the proband after sequencing the DKC1 gene. The mother was found to be carrier for the same mutation. She did not have any clinical manifestations. This is the commonest mutation worldwide responsible for X-linked variety of this disease and has been demonstrated for the first time in an native Indian patient.

Disqueratosis congénita ligada al cromosoma X / X-linked congenital dyskeratosis

La disqueratosis congénita es una genodermatosis muy poco frecuente, existiendo aproximadamente 180 casos reportados. Objetivo: Presentar el caso de un paciente de sexo masculino en quien se sospechó el diagnóstico basado en la presentación clínica, confirmado posteriormente mediante estudio molecular. Caso clínico: Escolar de sexo masculino con antecedentes de anemia refractaria a tratamiento e infecciones bacterianas severas, que se presentó clínicamente con hiperpigmentación cutánea reticular, distrofia ungueal, leucoplaquia y falla medular. En el estudio molecular se detectó una mutación del gen DKC1 que determina una sustitución aminoacídica en la posición 353 de Alanina por Valina. Discusión: La disqueratosis congénita es un desorden genético multisistémico, muy poco frecuente. Clínicamente se caracteriza por la presencia de hiperpigmentación cutánea de tipo reticular, distrofia ungueal, leucoplaquia de la mucosa oral y pancitopenia progresiva. La mutación detectada en este caso es una causa importante de Disqueratosis congénita en el mundo.

Dyskeratosis congenita is a rare genetic disorder with approximately 180 cases reported in the literature. Objective: To present the case of a boy, in whom the diagnosis was clinically suspected and later confirmed by molecular analysis of the Dyskerin gene. Clinical Case: A school age boy with a history of anemia resistant to treatment, and severe bacterial infections, who presented with reticulated pigmentation of the skin, nail dystrophy, oral leukoplakia and progressive pancitopenia. Molecular analysis revealed a mutation in the DKC1 gene, that results in an aminoacid change from alanine to valine. Conclusion: Dyskeratosis congenita is a rare inherited disease characterised by cutaneous reticulated hyperpigmentation, nail dystrophy, oral leukoplakia and progressive pancytopenia. The mutation detected in this patient is an important cause of dyskeratosis congenita worldwide.

A novel mutation in DKC1 gene in a patient with dyskeratosis congenita / 中华皮肤科杂志

Objective To detect the mutation in DKC1 gene in a patient with dyskeratosis congeni- ta.Methods Fifteen exons of DKC1 gene were amplified by polymerase chain reaction (PCR),and the products were screened for mutations by denaturing high performance liquid chromatography (DHPLC) technology,then DNA sequencing was performed for abnormal exons as shown by DHPLC.The gene muta- tions were verified within 100 unrelated male individuals without dyskeratosis congenita.Results An ab- normal DHPLC elution peak was found in exon 12 of DKC1 gene of the patient,but not in other family members or normal individuals.DNA sequencing showed a 1236G→T transition in DKC1 gene in the pa- tient,which resulted in a 412W→C substitution in DKC1.No mutation was found in other family members and normal individuals.Conclusion The 1236G→T transition in the patient is a novel mutation in DKC1 gene,which could be a causative factor of dyskeratosis congenita.