Blocking circ_0010235 suppresses acquired paclitaxel resistance of non-small cell lung cancer by sponging miR-512-5p to modulate FAM83F expression.

The occurrence of paclitaxel (PTX) resistance in nonsmall cell lung cancer (NSCLC) is a major challenge for NSCLC treatment. Circular RNAs (circRNAs) have been reported to associate with cancer resistance, but the role of circ_0010235 in PTX resistance of NSCLC is unclear. The expression of circ_0010235 and microRNA-512-5p (miR-512-5p) were determined by quantitative real-time PCR. Cell counting kit-8 assay, transwell assay and flow cytometry were performed to measure the PTX resistance, proliferation, migration, invasion and apoptosis of cells. All proteins were assessed via western blot analysis. The combination between miR-512-5p and circ_0010235 or FAM83F was predicted by the online database and confirmed by a dual-luciferase reporter assay. Angiogenesis assay was used to detect the ability of cells to form blood vessels. Animal experiments were employed to confirm the effect of circ_0010235 on NSCLC tumor growth in vivo. Circ_0010235 and FAM83F were upregulated in PTX-resistant NSCLC tissues and cells. Circ_0010235 knockdown suppressed the resistance to PTX, proliferation, angiogenesis and migration/invasion in A549/PTX and H1299/PTX cells but promoted apoptosis rate. MiR-512-5p could be sponged by circ_0010235, and its overexpression had an inhibition effect on the PTX resistance of NSCLC cells. FAM83F was a target of miR-512-5p and circ_0010235 could modulate FAM83F expression by sponging miR-512-5p. In vivo experiments revealed that silenced circ_0010235 could improve the sensitivity of the tumor to PTX. Therefore, these findings advocated targeting the circ_0010235/miR-512-5p/FAM83F axis as a potential therapeutic option for patients with NSCLC who are resistant to PTX.

TM4SF19-AS1 facilitates the proliferation of lung squamous cell carcinoma by recruiting WDR5 to mediate TM4SF19.

BACKGROUND: As reported, long non-coding RNAs are a pivotal player in lung squamous cell carcinoma (LSCC) progression. We noticed the remarkably upregulated transmembrane-4-l-six-family-19 antisense RNA 1 (TM4SF19-AS1) in LSCC and further demonstrated the function it played in LSCC and the possible molecular mechanism. METHODS: Via bioinformatics approach, we evaluated TM4SF19-AS1 and TM4SF19 levels in LSCC tissue, and real-time quantitative polymerase chain reaction (qRT-PCR) and Western blot revealed their mRNA and protein levels in LSCC cells. Cell Counting Kit-8 and colony formation assays analyzed the proliferation ability of LSCC cells, and cell adhesion ability was detected via cell adhesion assay. RNA immunoprecipitation and chromatin immunoprecipitation analyzed the underlying mechanism of TM4SF19-AS1 regulating its target, while methylation-specific PCR indicated the methylation level of TM4SF19-AS1. RESULTS: TM4SF19-AS1 was markedly upregulated in LSCC. Functional assays revealed that TM4SF19-AS1 could facilitate the proliferation and adhesion of LSCC. Besides, we revealed the mechanism of TM4SF19-AS1 regulation that it directly bound to WD repeat-containing protein 5 (WDR5), and was then recruited to TM4SF19 promoter region, which activated DNA demethylation, thereby suppressing malignant LSCC progression. CONCLUSION: Our research demonstrated that TM4SF19-AS1 affected LSCC cell proliferation by recruiting WDR5 to manipulate transmembrane-4-lsix-family-member-19 (TM4SF19), which offers a new observation on LSCC pathogenesis, indicating that TM4SF19-AS1 is able to be a promising target for LSCC treatment.

MicroRNA-466 regulates the proliferation, migration and invasion of the human lung cancer cells by targeting transcription factor RUNX2.

PURPOSE: Lung cancer causes significant mortality across the globe. This study aimed at the exploration of the regulatory role of microRNA (miR)-466 in lung cancer. METHODS: qRT-PCR analysis was used to infer the expression levels of miR-466 and Runt-related transcription factor 2 (RUNX2). CCK8 kit was used for assessment of cell proliferation. Colony forming assay was employed for examining the viability of cancer cells. The wound healing and Matrigel assays were used for investigating the rates of migration and invasion of cancer cells, respectively. Dual luciferase assay was performed to assess the interaction between miR-466 and RUNX2. Western blotting was performed to determine the protein expression. RESULTS: The results indicated that miR-466 is downregulated in lung cancer cells. Its overexpression led to significant decline of proliferation of cancer cells. The migration and invasion of lung cancer cells transfected with mir-466 mimics also got repressed. At molecular level, the regulatory role of miR-466 was exerted through the RUNX2 transcription factor whose silencing mimicked the effects of miR-466 overexpression. CONCLUSION: Taken all together, miR-466 suppression is associated with the growth and progression of lung cancer. The miR-466 overexpression declined the proliferation and metastasis of cancer cells and these effects were modulated through miR-466/RUNX2 molecular axis.

Local injection of lentivirus-delivered livinshRNA suppresses lung adenocarcinoma growth by inducing a G0/G1 phase cell cycle arrest.

The inhibitor of apoptosis protein (IAP) plays an important role in tumorigenesis and may be a potential target for cancer therapy. Livin, which belongs to this family, is highly expressed in various tumors. The previous study demonstrated that silencing Livin gene promoted lung cancer cell apoptosis; however, the effects on tumor growth suppression by targeting this gene in vivo, to thereby determine the efficacy of targeting Livin for patient therapy, have not been determined. This study injected lentivirus-delivered livinshRNA into established xenograft tumors derived from the lung adenocarcinoma cell line SPC-A-1 in BALB/C nude mice, the result showed that LivinshRNA down-regulated Livin expression effectively, induced tumor cell apoptosis, reduced tumor cell proliferation, and suppressed tumor growth dramatically, with a tumor volume inhibitory rate of (58.65±4.82)% and a tumor weight inhibitory rate of (47.44±1.64)%, but with less severe adverse reaction to the mouse. This study further demonstrated that Livin gene silencing induced a G0/G1-phase cell cycle arrest and cyclin D1 downregulation, which is a key regulator of the G0/G1- to S-phase transition. These findings suggest that LivinshRNA local injection may serve as a therapeutic method for patient treatment, and that LivinshRNA may suppress tumor growth by arresting the cell cycle in the G0/G1-phase.

[Effects of human Livin gene down-regulation by RNA interference on xenograft of transplantation tumor induced by SPC-A1 in nude mice].

OBJECTIVE: To explore the in vivo inhibitory effect of Livin gene silencing by RNA interference on xenograft of lung adenocarcinoma SPC-A-1 cells in BALB/C nude mice. METHODS: Three different BALB/C nude mice models were established by subcutaneously inoculating differently treated SPC-A-1 cells into 3 nude mice groups: the blank control group was inoculated with blank SPC-A-1 cells, while the negative group was inoculated with cells transfected with lentivirus-delivered negative shRNA, the experimental group was inoculated with cells with lentivirus-delivered Livin shRNA. Then the growth of tumors was observed, and the volume and weight of the tumors were measured at different time points. The curve of tumor growth was then described, and the inhibition rate was calculated. Livin gene expression in the tumor tissues was determined by RT-PCR and Immunohistochemistry. Cell apoptosis of tumor tissues was detected by TUNEL. RESULTS: Slower tumor growth, smaller tumor volume and lighter tumor weight were observed in the experimental group as compared to the blank and negative groups (F = 70.509, P < 0.01; F = 12.821, P < 0.01). The inhibition rate of tumor volume was (59.5 ± 3.4)%, and the inhibition rate of tumor weight was (71.1 ± 5.6)%. Livinα mRNA and Livinß mRNA expressions in the experimental group were significantly lower than the 2 control groups [(37.2 ± 1.6)% versus (63.3 ± 3.8)%, (66.1 ± 2.6)%; (29.4 ± 1.1)% versus (53.2 ± 3.4)%, (52.3 ± 3.1)% (F(α) = 45.309, P < 0.01; F(ß) = 30.076, P < 0.01)]. Livin protein expression level was also significantly lower than the blank and the negative groups [(15.3 ± 2.8)% versus (51.3 ± 2.1)%, (52.5 ± 2.5)%, F = 78.92, P < 0.01]. The apoptosis rate in the experimental group was significantly higher than that in the 2 control groups [(35.4 ± 3.2)% versus (5.4 ± 1.3)%, (8.6 ± 1.5)%, F = 14.509, P < 0.01]. CONCLUSION: The lentivirus-delivered Livin shRNA was shown to inhibit the proliferation of transplantation tumor of lung carcinoma effectively, and Livin may be a target for gene therapy in lung cancer.