RESUMEN
Analysis of ovarian cancer tissue and normal ovarian tissue revealed 31 RNA modifications with significant differences observed in cancer tissue compared with normal tissue. Moreover, we found Im and chm5U as characteristic RNA modifications in advanced and platinum-resistant ovarian cancers, respectively. Considering that these differences in RNA modifications may be due to the intra-tumour microenvironment, we xenografted the ovarian cancer cell line RMG-1 to create RMG-1 tumours and compared them with original RMG-1 cells. As a result, 14 of the 31 RNA modifications showed marked variations during tumorigenesis. Eight RNA modifications (m2,2G, t6A, m7G, m5U, m1G, i6A, m6t6A and m1A), which were upregulated in ovarian cancer tissues and in RMG-1-xenografted tumour, were also upregulated under hypoxic conditions. RNAseq analysis, using the matched RNA samples analysed for RNA modifications, showed that 2137 genes were highly expressed in ovarian cancer tissues compared with those in normal ovarian tissues. Of these, 134 genes, which were enriched in a gene set belonging to the hypoxia signalling pathway, were positively correlated with the above eight RNA modifications. These results suggest that the tumour microenvironment, including hypoxia, is important for cancer characteristic RNA modifications.
Asunto(s)
Neoplasias Ováricas , Humanos , Femenino , Neoplasias Ováricas/genética , Neoplasias Ováricas/metabolismo , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , ARN , Hipoxia/genética , Microambiente Tumoral/genéticaRESUMEN
Previously, we have revealed that the miR-130 family (miR-130b, miR-301a, and miR-301b) functions as an oncomiR in bladder cancer. The pharmacological inhibition of the miR-130 family molecules by the seed-targeting strategy with an 8-mer tiny locked nucleic acid (LNA) inhibits the growth, migration, and invasion of bladder cancer cells by repressing stress fiber formation. Here, we searched for a functionally advanced target sequence with LNA for the miR-130 family with low cytotoxicity and found LNA #9 (A(L)^i^i^A(L)^T(L)^T(L)^G(L)^5(L)^A(L)^5(L)^T(L)^G) as a candidate LNA. LNA #9 inhibited cell growth in vitro and in an in vivo orthotopic bladder cancer model. Proteome-wide tyrosine phosphorylation analysis suggested that the miR-130 family upregulates a wide range of receptor tyrosine kinases (RTKs) signaling via the expression of phosphorylated Src (pSrcTyr416). SILAC-based proteome analysis and a luciferase assay identified protein tyrosine phosphatase non-receptor type 1 (PTPN1), which is implicated as a negative regulator of multiple signaling pathways downstream of RTKs as a target gene of the miR-130 family. The miR-130-targeted LNA increased and decreased PTPN1 and pSrcTyr416 expressions, respectively. PTPN1 knockdown led to increased tumor properties (cell growth, invasion, and migration) and increased pSrcTyr416 expression in bladder cancer cells, suggesting that the miR-130 family upregulates multiple RTK signaling by targeting PTPN1 and subsequent Src activation in bladder cancer. Thus, our newly designed miR-130 family targeting LNA could be a promising nucleic acid therapeutic agent for bladder cancer.
Asunto(s)
Antineoplásicos/uso terapéutico , MicroARNs/antagonistas & inhibidores , Proteínas de Neoplasias/fisiología , Oligonucleótidos/uso terapéutico , Proteína Tirosina Fosfatasa no Receptora Tipo 1/fisiología , ARN Neoplásico/antagonistas & inhibidores , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Animales , Carcinoma de Células Transicionales/tratamiento farmacológico , Carcinoma de Células Transicionales/genética , Carcinoma de Células Transicionales/metabolismo , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Regulación Neoplásica de la Expresión Génica , Genes Reporteros , Humanos , Ratones , MicroARNs/genética , ARN Neoplásico/genética , Proteínas Tirosina Quinasas Receptoras/biosíntesis , Proteínas Tirosina Quinasas Receptoras/genética , Proteínas Recombinantes/metabolismo , Regulación hacia Arriba , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The human AlkB homolog family (ALKBH) of proteins play a critical role in some types of cancer. However, the expression and function of the lysine demethylase ALKBH4 in cancer are poorly understood. Here, we examined the expression and function of ALKBH4 in non-small-cell lung cancer (NSCLC) and found that ALKBH4 was highly expressed in NSCLC, as compared to that in adjacent normal lung tissues. ALKBH4 knockdown significantly induced the downregulation of NSCLC cell proliferation via cell cycle arrest at the G1 phase of in vivo tumour growth. ALKBH4 knockdown downregulated E2F transcription factor 1 (E2F1) and its target gene expression in NSCLC cells. ALKBH4 and E2F1 expression was significantly correlated in NSCLC clinical specimens. Moreover, patients with high ALKBH4 expression showed a poor prognosis, suggesting that ALKBH4 plays a pivotal tumour-promoting role in NSCLC.
