The Molecular Pathogenesis of Tumor-Suppressive miR-486-5p and miR-486-3p Target Genes: GINS4 Facilitates Aggressiveness in Lung Adenocarcinoma.

The involvement of passenger strands of miRNAs in the molecular pathogenesis of human cancers is a recent concept in miRNA research, and it will broaden our understanding of the molecular mechanisms of miRNA-mediated cancer. The analysis of our miRNA signature of LUAD revealed that both strands of pre-miR-486 (miR-486-5p and miR-486-3p) were downregulated in LUAD tissues. Ectopic expression of both miRNAs induced cell cycle arrest in LUAD cells, suggesting both strands of miRNAs derived from pre-miR-486 were tumor suppressive. Our in silico analysis showed a total of 99 genes may be under the control of both miRNAs in LUAD cells. Importantly, among these targets, the high expression of seven genes (MKI67, GINS4, RRM2, HELLS, MELK, TIMELESS, and SAPCD2) predicted a poorer prognosis of LUAD patients (p < 0.05). We focused on GINS4, a DNA replication complex GINS protein that plays an essential role in the initiation of DNA replication. Our functional assays showed that GINS4 was directly controlled by both strands of pre-miR-486, and its aberrant expression facilitated the aggressive behavior of LUAD cells. GINS4 is attractive as a therapeutic target for this disease. MiRNA analysis, including passenger strands, will further improve our understanding of the molecular pathogenesis of LUAD.

Minichromosome maintenance proteins in lung adenocarcinoma: Clinical significance and therapeutic targets.

Lung cancer is the most common cause of cancer-related death worldwide, accounting for 1.8 million deaths annually. Analysis of The Cancer Genome Atlas data showed that all members of the minichromosome maintenance (MCM) family (hexamers involved in DNA replication: MCM2-MCM7) were upregulated in lung adenocarcinoma (LUAD) tissues. High expression of MCM4 (P = 0.0032), MCM5 (P = 0.0032), and MCM7 (P = 0.0110) significantly predicted 5-year survival rates in patients with LUAD. Simurosertib (TAK-931) significantly suppressed the proliferation of LUAD cells by inhibiting cell division cycle 7-mediated MCM2 phosphorylation. This finding suggested that MCM2 might be a therapeutic target for LUAD. Moreover, analysis of the epigenetic regulation of MCM2 showed that miR-139-3p, miR-378a-5p, and miR-2110 modulated MCM2 expression in LUAD cells. In patients with LUAD, understanding the role of these miRNAs may improve prognoses.

Severe asthma remaining well-controlled after mepolizumab discontinuation: A case report and literature review.

Mepolizumab, a humanized anti-IL-5 monoclonal antibody used for severe asthma, results in a reduced rate of asthma exacerbation, improved lung function, reduced oral corticosteroid use, and improved quality of life. A 62-year-old man using high-dose inhaled corticosteroid visited our hospital because of poorly-controlled asthma. He had eosinophilia in peripheral blood and sputum, and high levels of fraction of exhaled nitric oxide. Therefore, he was treated with mepolizumab for severe asthma. Mepolizumab treatment resulted in significantly improved pulmonary function and reduced frequencies of asthma exacerbations. Because of his good asthma control, mepolizumab treatment was discontinued after 3 years. Since discontinuing mepolizumab, his asthma control has remained without exacerbation. Previous studies suggest that mepolizumab should be continued to sustain clinical benefits. However, cases of long-term controlled asthma have not been reported after mepolizumab withdrawal, and our case may be instructive.

MiR-15b-5p inhibits castration-resistant growth of prostate cancer cells by targeting the muscarinic cholinergic receptor CHRM3.

Cholinergic receptor muscarinic 3 (CHRM3)-mediated focal adhesion kinase/YES-associated protein (YAP) signalling is essential for the growth of castration-resistant prostate cancer (CRPC) cells. Here, we evaluated the molecular mechanisms through which CHRM3 overexpression facilitates castration-resistant growth. Small RNA sequencing combined with in silico analyses revealed that CHRM3 was a putative target of miR-15b-5p. Notably, androgen deprivation suppressed miR-15b-5p expression and increased CHRM3 expression. Moreover, miR-15b-5p bound directly to CHRM3 and inhibited YAP activation induced by CHRM3 stimulation. Furthermore, miR-15b-5p abolished the growth of CRPC cells induced by CHRM3 stimulation. We conclude that the miR-15b-5p/CHRM3/YAP signalling axis promotes the castration-resistant growth of prostate cancer.

MicroRNA signature of small-cell lung cancer after treatment failure: impact on oncogenic targets by miR-30a-3p control.

Small-cell lung cancer (SCLC) is associated with a high mortality rate and limited treatment efficacy. We created a microRNA (miRNA) expression signature by RNA sequencing using specimens from patients with SCLC who had failed treatment. Forty-nine miRNAs were downregulated in SCLC tissues and were candidate tumor-suppressive miRNAs. In this signature, both guide and passenger strands were downregulated for five miRNAs (miR-30a, miR-34b, miR-34c, miR-223, and miR-4529). Recent studies have revealed that passenger strands of miRNAs are involved in the molecular pathogenesis of human cancer. Although miR-30a-5p (the guide strand) has been shown to be a tumor-suppressive miRNA in various types of cancers, miR-30a-3p (the passenger strand) function is not well characterized in SCLC cells. We investigated the functional significance of miR-30a-3p and oncogenic genes regulated by miR-30a-3p in SCLC cells. Ectopic expression assays showed that miR-30a-3p expression inhibited cell proliferation and induced cell cycle arrest and apoptosis in two SCLC cell lines. Furthermore, in silico database searches and gene expression assays identified 25 genes as putative targets of miR-30a-3p in SCLC cells. Luciferase reporter assays revealed that downstream neighbor of SON (DONSON) was directly regulated by miR-30a-3p in SCLC cells. Knockdown of DONSON induced cell cycle arrest in SCLC cells and DONSON overexpression were detected in SCLC clinical samples. Analyzing the regulatory networks of tumor-suppressive miRNAs may lead to the identification of therapeutic targets in SCLC.

Regulation of Oncogenic Targets by Tumor-Suppressive miR-150-3p in Lung Squamous Cell Carcinoma.

Several recent studies have shown that both strands of certain miRNAs derived from miRNA duplexes are involved in cancer pathogenesis. Our own recent studies revealed that both strands of the miR-150 duplex act as tumor-suppressive miRNAs in lung adenocarcinoma (LUAD) through the targeting of several oncogenes. The aim of the study here was to further investigate the tumor-suppressive roles of miR-150-3p (the passenger strand) in lung squamous cell carcinoma (LUSQ) and its control of cancer-promoting genes in LUSQ cells. The downregulation of miR-150-3p in LUSQ tissues was confirmed by data in The Cancer Genome Atlas (TCGA). The ectopic expression of miR-150-3p attenuated cancer cell aggressive features, e.g., cell cycle arrest, migration and invasive abilities. Our target search strategy successfully identified a total of 49 putative targets that were listed as subjects of miR-150-3p regulation in LUSQ cells. Interestingly, among these targets, 17 genes were categorized as related to the "cell cycle" based on Gene Ontology (GO) classification, namely CENPA, CIT, CCNE1, CCNE2, TIMELESS, BUB1, MCM4, HELLS, SKA3, CDCA2, FANCD2, NUF2, E2F2, SUV39H2, CASC5, ZWILCH and CKAP2). Moreover, we show that the expression of HELLS (helicase, lymphoid specific) is directly controlled by miR-150-3p, and its expression promotes the malignant phenotype of LUSQ cells.

Molecular Signature of Small Cell Lung Cancer after Treatment Failure: The MCM Complex as Therapeutic Target.

Small cell lung cancer (SCLC) is a highly aggressive cancer, and patients who become refractory to first-line treatment have a poor prognosis. The development of effective treatment regimens is urgently needed. In this study, we identified a gene expression signature of SCLC after treatment failure using SCLC clinical specimens (GEO accession number: GSE162102). A total of 1,136 genes were significantly upregulated in SCLC tissues. These upregulated genes were subjected to KEGG pathway analysis, and "cell cycle", "Fanconi anemia", "alcoholism", "systemic lupus erythematosus", "oocyte meiosis", "homologous recombination", "DNA replication", and "p53 signaling" were identified as the enriched pathways among the genes. We focused on the cell cycle pathway and investigated the clinical significance of four genes associated with this pathway: minichromosome maintenance (MCM) 2, MCM4, MCM6, and MCM7. The overexpression of these MCM genes was confirmed in SCLC clinical specimens. Knockdown assays using siRNAs targeting each of these four MCM genes showed significant attenuation of cancer cell proliferation. Moreover, siRNA-mediated knockdown of each MCM gene enhanced the cisplatin sensitivity of SCLC cells. Our SCLC molecular signature based on SCLC clinical specimens after treatment failure will provide useful information to identify novel molecular targets for this disease.

FAM64A: A Novel Oncogenic Target of Lung Adenocarcinoma Regulated by Both Strands of miR-99a (miR-99a-5p and miR-99a-3p).

Lung adenocarcinoma (LUAD) is the most aggressive cancer and the prognosis of these patients is unfavorable. We revealed that the expression levels of both strands of miR-99a (miR-99a-5p and miR-99a-3p) were significantly suppressed in several cancer tissues. Analyses of large The Cancer Genome Atlas (TCGA) datasets showed that reduced miR-99a-5p or miR-99a-3p expression is associated with worse prognoses in LUAD patients (disease-free survival (DFS): p = 0.1264 and 0.0316; overall survival (OS): p = 0.0176 and 0.0756, respectively). Ectopic expression of these miRNAs attenuated LUAD cell proliferation, suggesting their tumor-suppressive roles. Our in silico analysis revealed 23 putative target genes of pre-miR-99a in LUAD cells. Among these targets, high expressions of 19 genes were associated with worse prognoses in LUAD patients (OS: p < 0.05). Notably, FAM64A was regulated by both miR-99a-5p and miR-99a-3p in LUAD cells, and its aberrant expression was significantly associated with poor prognosis in LUAD patients (OS: p = 0.0175; DFS: p = 0.0276). FAM64A knockdown using siRNAs suggested that elevated FAM64A expression contributes to cancer progression. Aberrant FAM64A expression was detected in LUAD tissues by immunostaining. Taken together, our miRNA-based analysis might be effective for identifying prognostic and therapeutic molecules in LUAD.

Effect of bevacizumab on brain radiation necrosis in anaplastic lymphoma kinase-positive lung cancer.

Central nervous system (CNS) metastases from anaplastic lymphoma kinase (ALK)-positive lung cancer often results in failure of ALK-tyrosine kinase inhibitor (TKI) therapy. Patients with uncontrolled CNS metastases receive radiation therapy, which sometimes causes brain radiation necrosis. We added bevacizumab (15 mg/kg, every 3-4 weeks) to the regimen of four ALK-positive lung cancer patients with brain radiation necrosis who were receiving ALK-TKI therapy. A decrease in brain radiation necrosis was seen in all the patients, and an improvement in symptoms was seen in three patients. In one patient who was receiving corticosteroid therapy, we could taper the dose and subsequently discontinue it. While one patient discontinued bevacizumab because of adverse events, the other three continued with the treatment. Therefore, the combination of bevacizumab with ALK-TKI seems to be an effective, manageable, and tolerable treatment for brain radiation necrosis.