Long Non-Coding RNA NANCI/NKX2-1 Duplex Impacts Prognosis in Stage I Non-Small-Cell Lung Cancer

Estrogen receptor beta promotes lung cancer invasion via increasing CXCR4 expression

Lung cancer is one of the most lethal malignant tumors in the world. The high recurrence and mortality rate make it urgent for scientists and clinicians to find new targets for better treatment of lung cancer. Early studies indicated that estrogen receptor β (ERβ) might impact the progression of non-small-cell lung cancer (NSCLC). However, the detailed mechanisms, especially its linkage to the CXCR4-mediated cell invasion, remain unclear. Here we found that ERβ could promote NSCLC cell invasion via increasing the circular RNA (circRNA), circ-TMX4, expression via directly binding to the 5′ promoter region of its host gene TMX4. ERβ-promoted circ-TMX4 could then sponge and inhibit the micro RNA (miRNA, miR), miR-622, expression, which can then result in increasing the CXCR4 messenger RNA translation via a reduced miRNA binding to its 3′ untranslated region (3′UTR). The preclinical study using an in vivo mouse model with orthotopic xenografts of NSCLC cells confirmed the in vitro data, and the human NSCLC database analysis and tissue staining also confirmed the linkage of ERβ/miR-622/CXCR4 signaling to the NSCLC progression. Together, our findings suggest that ERβ can promote NSCLC cell invasion via altering the ERβ/circ-TMX4/miR-622/CXCR4 signaling, and targeting this newly circ-TMX4/miR-622/CXCR4 signaling may help us find new treatment strategies to better suppress NSCLC progression.

Long Noncoding RNA LINC01426 Sequesters microRNA-519d-5p to Promote Non-Small Cell Lung Cancer Progression by Increasing ETS1 Expression

PURPOSE

Recent studies have identified important roles for long intergenic non-protein coding RNA 1426 (LINC01426) in glioma and clear cell renal cell carcinoma. The present study evaluated the expression profile of LINC01426 in non-small cell lung cancer (NSCLC) tissues and cell lines. Furthermore, the function of LINC01426 in NSCLC and the molecular mechanisms involved were extensively studied.

METHODS

The abundance of LINC01426 in NSCLC tissues and cell lines was determined using quantitative reverse transcription-polymerase chain reaction. The cell counting kit-8 assay, flow cytometry, transwell experiments for migration and invasion, and xenograft tumor model were used to assess the function of LINC01426 in NSCLC cells. Mechanistic studies were performed using the luciferase reporter assay and RNA immunoprecipitation.

RESULTS

Significant LINC01426 upregulation was observed in NSCLC tissues and cell lines. Silencing LINC01426 inhibited proliferation, migration, and invasion of NSCLC cells and facilitated cell apoptosis in vitro. Furthermore, interference of LINC01426 restricted tumor growth of NSCLC cells in vivo. In addition, LINC01426 showed the ability to directly bind to microRNA-519d-5p (miR-519d-5p) and act as a molecular sponge for miR-519d-5p in NSCLC cells. Furthermore, the ETS proto-oncogene 1 (ETS1) was identified as a direct target of miR-519d-5p and LINC01426 could indirectly upregulate ETS1 expression by sponging miR-519d-5p. Moreover, the cancer-inhibiting activities of LINC01426 knockdown in NSCLC cells were partially offset by miR-519d-5p inhibition.

CONCLUSION

LINC01426 increases ETS1 expression by sequestering miR-519d-5p, thereby aggravating the malignant progression of NSCLC. The LINC01426/miR-519d-5p/ETS1 competing endogenous RNA pathway may provide a target for designing therapeutic agents for NSCLC treatment.

Long Intergenic Non-Protein Coding RNA 01089 Weakens Tumor Proliferation, Migration, and Invasion by Sponging miR-3187-3p in Non-Small Cell Lung Cancer

Background

Long non-coding RNAs (lncRNAs), a class of endogenous non-coding RNAs, play an important role in the development and metastasis of non-small cell lung cancer (NSCLC). However, the function and mechanism of action of long intergenic non-protein coding RNA 1089 (LINC01089) in NSCLC remains unclear. This study aimed to identify the role of LINC01089 in cell proliferation, migration, and invasion of NSCLC.

Methods

Expression of LINC01089 and the relationship between LINC01089 and overall survival (OS) in NSCLC were determined using GEPIA 2.0. Similarly, microRNAs (miRNAs) that showed increased expression in NSCLC and correlated with OS were identified using the online OncomiR cancer database. Target miRNAs of LINC01089 were predicted using starBase. Cell models of LINC01089 and miR-3187-3p overexpression were constructed using transfection. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to analyze the expression of LINC01089 and miR-3187-3p. MTS assay was used to assess cell proliferation. Transwell was used for migration and invasion assays.

Results

LINC01089 expression was significantly reduced in NSCLC tissues and cells. Gain-of-function studies further demonstrated that LINC01089 overexpression inhibited proliferation, migration, and invasion of lung cancer cell lines, A549 and SK-MES-1. Based on starBase prediction and subsequent verification, we revealed that miR-3187-3p is a target miRNA of LINC01089. Additionally, miR-3187-3p expression was significantly increased in NSCLC tissues and cells. Overexpression of miR-3187-3p promoted proliferation, migration, and invasion of A549 and SK-MES-1 cells, thereby reversing the effect of LINC01089.

Conclusion

LINC01089 attenuates tumor proliferation, migration, and invasion by sponging miR-3187-3p in NSCLC. LINC01089 acts as a tumor suppressor and represents a potential therapeutic target in NSCLC.