miRNA-regulated expression of oncogenes and tumor suppressor genes in the cisplatin-inhibited growth of K562 cells

Abstract

Abstract.To explore the mechanism of apoptosis induced by cisplatin, the expression of microRNAs (miRNAs) and regulating genes in K562 cells was analyzed using reverse transcription PCR, quantitative real-time PCR and enzymelinked immunosorbent assays. Our results showed that miR-16, miR-34a-c, miR-17-5p and miR-125 were upregulated, and their associated oncogenes (BCL2, E2F1 and E2F3, respectively) were down-regulated after cisplatin treatment. We also showed that miR-106 and miR-150 were down-regulated while their target genes (RB1 and P53, respectively) were up-regulated after cisplatin treatment. Moreover, miR-16, miR-34a-c and miR-17-5p proved to be upstream factors, regulating the expression of BCL2, E2F1 and E2F3, respectively. The oncogene E2F3 was downregulated when RB1 expression was increased after treatment with antisense oligonucleotides (ASO). Similarly, BCL2 and E2F3 were down-regulated when P53 expression was elevated by ASO treatment. The study demonstrated that cisplatin induces K562 cells to apoptosis by reducing miR-106 which up-regulates RB1 or by inhibiting miR-150 which increases P53 expression. IntroductionCisplatin [cis-diamminedichloroplatinum (II), CDDP] has been used in numerous studies to induce the apoptosis of carcinoma cells. Cells, growth-arrested by cisplatin treatment, showed a higher spontaneous cell death rate than that of untreated proliferating cells. Cisplatin is an effective chemotherapeutic agent that elicits its antineoplastic activity by binding to DNA and disrupting template functions (1). Studies have shown that cisplatin strongly inhibits the decatenation activity of topoisomerase II (2), which is critical for relieving the torsional stress that occurs during replication and transcription and for daughter strand separation during mitosis. Cisplatin can also regulate the expression of oncogenes or tumor suppressor genes to induce tumor cell apoptosis. Likewise, these genes can predict the cisplatin sensitivity of cancer cell lines. Cisplatin was found to induce p53-dependent Fas-associated death domain-like interleukin-1ß-converting enzyme (FLICE)-like inhibitory protein (FLIP) degradation in chemosensitive ovarian cancer cells. A recent study demonstrated that cisplatin induces the PIDD (p53-induced protein with a death domain)-dependent activation of caspase-2. In turn, caspase-2 cleaves and activates Bid, resulting in the oligomerization of Bak and the release of cytochrome c, resulting in a synergistic induction of cisplatininduced cytotoxicity (3). Farnebo et al found that single nucleotide polymorphisms in the DNA repair genes XRCC3241 and XPD751 influence the intrinsic cisplatin sensitivity and that XRCC3241, XPD751, EGFR, Hsp70, Bax and Bcl-2 predict the cisplatin sensitivity of head and neck cancer cell lines (4).A family of 20-to 22-nucleotide (nt) noncoding RNAs termed microRNAs (miRNAs) has been identified in eukaryotic organisms ranging from nematodes to humans (5-7). After maturation, these small RNAs are incorporated into the RNA-induced silencing comp...

Role of microRNA-150 in solid tumors

“…miR-150 has been previously reported to be differentially expressed in various hematopoietic cell lineages of a specific developmental stage or characteristically up-or downregulated in various types of hematopoietic malignancies, including leukemia, lymphoma and myelodysplastic syndrome (14). In chronic myeloid leukemia (CML), miR-150 has been demonstrated to be involved in the mechanism of apoptosis induced by cisplatin in the human CML cell line, K562 (18). Xie et al (18)demonstrated a negative correlation between the expression levels of miR-150 and p53 following treatment of K562 cells with cisplatin, indicating that cisplatin induced apoptosis in the K562 cells by inhibiting miR-150 expression, which then upregulated p53 expression.…”

Downregulation of TrkA protein expression by miRNA-92a promotes the proliferation and migration of human neuroblastoma cells

“…Studies have revealed that miRNA may affect a multitude of target genes and that one target gene may be regulated by multiple miRNA molecules (17)(18)(19). The miR-17-92 cluster has been considered to be the most effective carcinogenic miRNA, and hundreds of target genes of this cluster have been reported (20)(21)(22)(23).…”

Regulation of Glucose Phosphate Isomerase by the 3′UTR-Specific miRNAs miR-302b and miR-17-5p in Chicken Primordial Germ Cells1

“…Overexpression of miR-302 downregulated TP63, one of its target genes, and inhibition of miR-302 upregulated TP63 in germ cell tumors [32]. Overexpression of miR-17-5p downregulated E2F transcription factor 1 (E2F1), and inhibition of miR-17-5p upregulated E2F1 in K562 cells [38]. Glucose energy and metabolism are crucial for embryonic stem cells, induced pluripotent stem cells, and germ cells [11][12][13], and a variety of miRNAs play a role in the regulation of glucose metabolism in the pancreas, liver, brain, muscle, and adipose tissue [8,16].…”