BACKGROUND: Non-small cell lung cancer (NSCLC) is the most common cancer worldwide. Circular RNAs (circRNAs) are recently identified as important gene regulators with critical roles in cancer biology. In this study, we focus on the effect of circ_0000376 targeting miR-384 on malignant phenotypes of NSCLC cells. METHODS: Circ_0000376 and miR-384 expression in NSCLC tissue samples were measured using qRT-PCR. The association between pathological parameters and the circ_0000376 expression was analyzed as well. Human NSCLC cell lines A549 and NCI-H460 were used as cell models. CCK-8 and BrdU assay were used to assess the effect of circ_0000376 on NSCLC cell line proliferation and drug sensitivity. Transwell assay was conducted to detect the effect of circ_0000376 on migration and invasion. Further, luciferase reporter assay was employed to validate the targeting of miR-384 by circ_0000376. RESULTS: Circ_0000376 expression in NSCLC clinical samples was up-regulated and this was linked to unfavorable pathological parameters. Circ_0000376 markedly accelerated the proliferation and metastasis, and enhanced chemoresistance of NSCLC cells. Mechanically, circ_0000376 overexpression could bind with miR-384 and repress its expression. CONCLUSIONS: Circ_0000376 is a newly discovered oncogenic circRNA in NSCLC, and can be potentially regarded as a diagnostic biomarker and therapy target.

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Background The standard treatment for advanced gastric/gastroesophageal junction cancer (AGC/GEJC) is palliative chemotherapy combined with targeted therapy. The SOX regimen (S-1 plus oxaliplatin) is recommended as neoadjuvant or palliative first-line chemotherapy in Asian patients. Apatinib, an oral VEGFR tyrosine kinase inhibitor, is associated with additional survival benefit as third- or subsequent-line therapy. However, the median overall survival time of AGC/GEJC is only 8–11 months in the West and 13–17 months in East Asia/Japan, even with the application of anti-angiogenic agents. Hence, the multimodal and individual management of patients is challenging standards to improve prognosis, including the preferential use of low-dose anti-angiogenic drugs and immunotherapy, as well as the application of multi-disciplinary treatment (MDT)-directed conversion therapy. Methods/Design This single-center study was designed to combine low-dose apatinib with camrelizumab plus the SOX regimen in diagnosed potentially resectable and initially unresectable AGC/GEJC. This a prospective, open-label, single-arm, dose escalation and extension phase Ib clinical trial, conducted in Jiangsu Province Hospital, beginning from June 2020. All patients will first receive this combined regimen (3 weeks/cycle) for at most eight cycles, then apatinib and camrelizumab in maintenance therapy until disease progression, intolerable toxicity, death, a maximum 2 years of treatment or discontinuation for any reason. Follow-up and evaluation will be carried out regularly. If surgery is allowed by MDT discussions, oral apatinib will be discontinued during the last preoperative cycle. The primary endpoints are the objective response rate and maximum tolerated dose according to the Response Evaluation Criteria In Solid Tumors (RECIST) criteria (version 1.1) and the Common Terminology Criteria for Adverse Events (CTCAE) criteria (version 5.0). Discussion This study will assess the response and side effects of AGC/GEJC patients in the use of low-dose apatinib combined with camrelizumab and the SOX regimen, and this combined therapy is expected to be a feasible and optimized first-line treatment option. In addition, this study will provide robust evidence and novel ideas for conversion therapy. Trial Registration ChiCTR.gov.cn: ChiCTR2000034109.

Breast cancer (BC) is regarded as the major cause of cancer-associated deaths in women. Paclitaxel exerts a critical impact on the chemotherapy of BC, but the resistance to paclitaxel becomes a great obstacle in treating the disease. It is reported that noncoding RNA nuclear receptor binding SET domain protein 1 (NSD1) plays a significant role in drug resistance; however, the special role of NSD1 in paclitaxel-resistant BC is unclear. Human BC cell line MCF-7 was used to establish paclitaxel-resistant BC cells (MCF-7/PR). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) displayed that NSD1 and F-box and leucine-rich repeat protein 11 (FBXL11) were highly expressed in BC tissues. Western blotting was utilized for protein level assessment. Cell counting kit-8 (CCK-8), Transwell, wound healing assays, and animal experiments were conducted to examine the influence of NSD1 or FBXL11 on the malignant behaviors of BC in vitro and in vivo , respectively. Transfected MCF-7/PR cells were injected subcutaneously into BALB/c nude mice with or without treatment of paclitaxel. The nuclear factor kappa B (NF-kB) activity was evaluated by the luciferase reporter assay. Results showed that NSD1 knockdown inhibited the epithelial-mesenchymal transition (EMT), migration and invasiveness of BC in vitro , which was rescued by FBXL11 overexpression. Furthermore, NSD1 silencing promoted paclitaxel sensitivity of paclitaxel-resistant BC cells and suppressed tumor growth and paclitaxel resistance in vivo . NSD1 knockdown reduced NF-kB activity, while FBXL11 inhibition markedly increased NF-kB activity. Collectively, NSD1 facilitates the EMT, migration and invasion in paclitaxel-resistant BC cells via regulating NF-kB and FBXL11.