Knockdown of circLRWD1 weakens DDP resistance via reduction of SIRT5 expression through releasing miR-507 in non-small cell lung cancer.

Cisplatin (DDP) is an antineoplastic agent for non-small cell lung cancer (NSCLC). Hsa_circ_0081664 (circLRWD1) is overexpressed in DDP-resistant NSCLC cells, but its function is unclear. Thus, this study is to investigate whether circLRWD1 participates in DDP resistance in NSCLC. Changes in circLRWD1 expression were determined by real-time quantitative PCR. Effects of circLRWD1 inhibition on DDP-resistant NSCLC cell viability, proliferation, migration, invasion, and apoptosis were analyzed. The sponge function of circLRWD1 was predicted by bioinformatics analysis and verified by dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays. The function of circLRWD1 in DDP resistance was verified by xenograft models. CircLRWD1 was unconventionally overexpressed in DDP-resistant NSCLC samples and cells. Moreover, circLRWD1 silencing decreased IC 50 value, restrained cell proliferation, reduced cell migration and invasion, and facilitated cell apoptosis in DDP-resistant NSCLC cells. Also, circLRWD1 knockdown elevated DDP-resistant NSCLC cell sensitivity to DDP in xenograft models. Furthermore, circLRWD1 regulated SIRT5 expression via adsorbing miR-507. SIRT5 overexpression weakened circLRWD1 silencing-mediated suppression of cell resistance to DDP in DDP-resistant NSCLC cells. In conclusion, circLRWD1 elevated SIRT5 expression via adsorbing miR-507, resulting in promoting NSCLC cell resistance to DDP, providing evidence to explain the significant role of circLRWD1 in DDP resistance in NSCLC.

Hsa_circRNA_0017620 regulated cell progression of non-small-cell lung cancer via miR-520a-5p/KRT5 axis.

BACKGROUND: CircRNA is a very important functional RNA that plays an important role in the development and metabolism of cancer. However, the study of circRNA in NSCLC has not been fully elucidated. METHODS: The expression of hsa_circ_0017620, SFMBT2, miR-520a-5p, and KRT5 was determined using qRT-PCR. KRT5, Twist1, E-cadherin, and Ki67 protein expression were measured with western blot. The positive expression rates of Ki67 and Vimentin were determined by immunohistochemistry assay. 5-Ethynyl-2'-deoxyuridine (EdU), colony formation, and MTT assays were used to assess cell proliferation. Transwell migration and invasion assay were applied to determine cell migration and invasion. Dual-luciferase reporter and RNA immunoprecipitation assays were used to verify the relationship among hsa_circ_0017620, miR-520a-5p, and KRT5. The animal experiment was used to ensure the effects of hsa_circ_0017620 on tumor growth in vivo. RESULTS: Hsa_circ_0017620 was upregulated in NSCLC cells and tissues. MiR-520a-5p had been verified to be a target miRNA of hsa_circ_0017620 and KRT5 had been verified to be a target mRNA of miR-520a-5p in NSCLC cells. Knockdown of hsa_circ_0017620 inhibited cell proliferation, migration, and invasion in NSCLC cells, which was reversed by downregulating miR-520a-5p or upregulating KRT5 in NSCLC. Overexpression of hsa_circ_0017620 had opposite effects in NSCLC. Moreover, hsa_circ_0017620 silencing inhibited tumor growth in vivo of NSCLC. CONCLUSION: In this study, we found that hsa_circ_0017620 played an important role in NSCLC progression. Hsa_circ_0017620 regulated cell proliferation, invasion, and migration through targeting miR-520a-5p/KRT5 axis in NSCLC, providing a potential new target for the treatment and diagnosis of NSCLC.

Circ_0016760 accelerates non-small-cell lung cancer progression through miR-646/AKT3 signaling in vivo and in vitro.

BACKGROUND: Currently, the prognosis of non-small-cell lung cancer (NSCLC) patients remains dismal due to recurrence and metastasis. The purpose of our study was to explore the role of circular RNA_0016760 (circ_0016760) in NSCLC progression and its associated mechanism. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was implemented to measure the expression of circ_0016760, microRNA-646 (miR-646) and AK strain thymoma serine/threonine kinase 3 (AKT3). The protein level of AKT3 was examined by Western blot assay. Cell Counting Kit 8 assay, transwell assays, and flow cytometry were conducted to analyze cell proliferation, metastasis, and apoptosis. Dual-luciferase reporter assay was used to confirm the interactions that were predicted by bioinformatics software (Circular RNA Interactome and TargetScan). A xenograft tumor model was built to investigate the role of circ_0016760 in vivo. RESULTS: Circ_0016760 and AKT3 were highly expressed in NSCLC tissue specimens and cell lines. Circ_0016760 interference suppressed cell proliferation, migration, and invasion and promoted the apoptosis of NSCLC cells. Circ_0016760 interacted with miR-646 and negatively regulated its expression. MiR-646 silencing partly counteracted circ_0016760 knockdown-mediated influences in NSCLC cells. MiR-646 bound to the AKT3 3' untranslated region in NSCLC cells, and miR-646 overexpression-induced effects in NSCLC cells were partly overturned by the addition of AKT3 overexpression plasmid. Circ_0016760 silencing reduced the expression of AKT3 through enhancing miR-646 expression. Circ_0016760 knockdown suppressed NSCLC tumor growth in vivo. CONCLUSION: Circ_0016760 played an oncogenic role to promote the proliferation, migration, and invasion and restrained the apoptosis of NSCLC cells via miR-646/AKT3 signaling.

Se-Enriched Cordyceps militaris Inhibits Cell Proliferation, Induces Cell Apoptosis, And Causes G2/M Phase Arrest In Human Non-Small Cell Lung Cancer Cells.

BACKGROUND: The anticancer effects of cordyceps on various tumors have been reported. However, little is known about the role of selenium (Se)-enriched Cordyceps militaris in non-small cell lung cancer (NSCLC). In this study, the effects of Se-enriched Cordyceps militaris on cell proliferation, cell apoptosis and cell cycle in NSCLC cell line NCI-H292 and A549 were investigated. METHODS: CCK-8 assay was used to determine the appropriate concentrations of Se-enriched Cordyceps militaris in NSCLC (namely NCI-H292 and A549) cells. Colony formation assay, flow cytometric and Hoechst 33342 staining assays, and flow cytometric analysis were separately employed to assess the effect of increased Se-enriched Cordyceps militaris on NSCLC cell viability, cell apoptosis and cell-cycle distribution. Finally, the qPCR and Western blot assays were, respectively, applied to evaluate the effects of Se-enriched Cordyceps militaris on the expression of pro-apoptotic member BAX and the anti-apoptotic member BCL-2, as well as of G2/M cell cycle regulatory proteins CDK1 and cyclin B1. RESULTS: The concentration of Se-enriched Cordyceps militaris was 0, 4, 8, 12 mg/mL for NCI-H292 cells, and 0, 12.5, 25, 50 mg/mL for A549 cells. NSCLC cells treated with increased Se-enriched Cordyceps militaris showed the inhibited cell viability. Se-enriched Cordyceps militaris induced NSCLC cell apoptosis in concentration-dependent manner. Consistently, Se-enriched Cordyceps militaris diminished the ratio of anti-apoptotic member BCL-2 and pro-apoptotic member BAX at mRNA and protein levels in NSCLC cells. The percentage in G2/M phase was increased in NSCLC cells treated with increased Se-enriched Cordyceps militaris. Downregulation of G2/M cell cycle regulatory proteins CDK1 and cyclin B1 at mRNA and protein levels in NSCLC cells further confirmed the effects of Se-enriched Cordyceps militaris on cell cycle. CONCLUSION: This study demonstrated the inhibitory role of Se-enriched Cordyceps militaris in cell proliferation and its facilitating role in cell apoptosis and cell cycle in NSCLC cells, suggesting an alternative therapeutic strategy for NSCLC treatment.

Conservative surgery plus axillary radiotherapy vs. modified radical mastectomy in patients with stage I breast cancer.

BACKGROUND: The objective of this study was to explore the effect of conservative surgery plus postoperative axillary radiotherapy without axillary lymph node dissection vs. modified radical mastectomy in patients with stage I breast cancer. PATIENTS AND METHODS: In this study, 186 patients with stage I breast cancer were enrolled. Among them, 98 patients underwent breast-conserving surgery without axillary node dissection. From the first day after surgery, each of them received 6 cycles of CMF (cyclophosphamide, methotrexate, 5-fluorouracil) chemotherapy, and thereafter radical radiotherapy for 5 to 6 weeks. Eighty-eight patients received modified radical mastectomy with postoperative chemotherapy and radiotherapy. The clinical data of these 186 patients were analyzed. RESULTS: There was no significant difference (P > .05) in local recurrence and survival rates between the conservative plus axillary radiotherapy group and the modified radical mastectomy group, although a significantly greater incidence of upper limb dysfunction and edema were observed in the modified mastectomy group (P < .05). CONCLUSION: The efficacy of conservative surgery plus axillary radiotherapy alone is superior to that of axillary node dissection for stage I breast cancer patients.