RESUMO
Long noncoding RNAs (lncRNAs) are deregulated in human cancers and are associated with disease progression. Plasmacytoma Variant Translocation 1 (PVT1), a lncRNA, is located adjacent to the gene MYC, which has been linked to multiple myeloma (MM). PVT1 is expressed in MM and is associated with carcinogenesis. However, its role and regulation remain uncertain. We examined PVT1/MYC expression using real-time PCR in plasma cells purified from 59 monoclonal gammopathy of undetermined significance (MGUS) and 140 MM patients. The MM cell lines KMS11, KMS12PE, OPM2, and RPMI8226 were treated with JQ1, an MYC super-enhancer inhibitor, or MYC inhibitor 10058-F4. The expression levels of PVT1 and MYC were significantly higher in MM than in MGUS (p < 0.0001) and were positively correlated with disease progression (r = 0.394, p < 0.0001). JQ1 inhibited cell proliferation and decreased the expression levels of MYC and PVT1. However, 10054-F4 did not alter the expression level of PVT1. The positive correlation between MYC and PVT1 in patients, the synchronous downregulation of MYC and PVT1 by JQ1, and the lack of effect of the MYC inhibitor on PVT1 expression suggest that the expression of these two genes is co-regulated by a super-enhancer. Cooperative effects between these two genes may contribute to MM pathogenesis and progression.
Assuntos
Carcinogênese/genética , Proteínas de Ciclo Celular/genética , Progressão da Doença , Gamopatia Monoclonal de Significância Indeterminada/genética , Mieloma Múltiplo/genética , RNA Longo não Codificante/genética , Fatores de Transcrição/genética , Acetamidas/farmacologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Azepinas/farmacologia , Proteínas de Ciclo Celular/antagonistas & inibidores , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Inativação Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Gamopatia Monoclonal de Significância Indeterminada/patologia , Mieloma Múltiplo/patologia , Plasmócitos/metabolismo , Proteínas Proto-Oncogênicas c-myc/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-myc/genética , Tiazóis/farmacologia , Fatores de Transcrição/antagonistas & inibidores , Triazóis/farmacologia , Adulto JovemRESUMO
Acute myeloid leukemia (AML) with granulocytic sarcoma (GS) is characterized by poor prognosis; however, its underlying mechanism is unclear. Bone marrow samples from 64 AML patients (9 with GS and 55 without GS) together with AML cell lines PL21, THP1, HL60, Kasumi-1, and KG-1 were used to elucidate the pathology of AML with GS. RNA-Seq analyses were performed on samples from seven AML patients with or without GS. Gene set enrichment analyses revealed significantly upregulated candidates on the cell surface of the GS group. Expression of the adhesion integrin α7 (ITGA7) was significantly higher in the GS group, as seen by RT-qPCR (p = 0.00188) and immunohistochemistry of bone marrow formalin-fixed, paraffin-embedded (FFPE) specimens. Flow cytometry revealed enhanced proliferation of PL21 and THP1 cells containing surface ITGA7 in the presence of laminin 211 and stimulated ERK phosphorylation; this effect was abrogated following ITGA7 knockdown or ERK inhibition. Overall, high ITGA7 expression was associated with poor patient survival (p = 0.0477). In summary, ITGA7 is highly expressed in AML with GS, and its ligand (laminin 211) stimulates cell proliferation through ERK signaling. This is the first study demonstrating the role of integrin α7 and extracellular matrix interactions in AML cell proliferation and extramedullary disease development.
