Knockdown of lncRNA TUC338 inhibits esophageal cancer cells migration and invasion

Cancer-associated fibroblasts secret extracellular vesicles to support cell proliferation and epithelial-mesenchymal transition in laryngeal squamous cell carcinoma

As the critical components of tumor microenvironment, cancer-associated fibroblasts (CAFs) support the development of various type of cancers, including laryngeal squamous cell carcinoma (LSCC), but the detailed molecular mechanisms by which cancer-associated fibroblasts interact with LSCC cells to facilitate its progression have not been fully uncovered. In the present study, by analyzing the contents from normal fibroblasts (NFs) and cancer-associated fibroblasts-derived extracellular vesicles (EVs) with Real-Time qPCR analysis, we found that the tumor-initiating LncRNA TUC338 was significantly upregulated in the cancer-associated fibroblasts-derived extracellular vesicles, compared to the normal fibroblasts-secreted extracellular vesicles. Further experiments confirmed that cancer-associated fibroblasts-derived extracellular vesicles promoted cell proliferation, colony formation abilities, epithelial-mesenchymal transition (EMT) and tumorigenesis of LSCC cells via delivering LncRNA TUC338. The mechanical experiments verified that LncRNA TUC338 was stabilized by METTL3/YTHDF1-mediated N6-methyladenosine (m6A) modifications, and elevated LncRNA TUC338 sponged miR-8485 to upregulate chromobox homolog 2 (CBX2) in LSCC cells in a competing endogenous RNA mechanisms-dependent manner. Moreover, our rescue experiments evidenced that cancer-associated fibroblasts-derived LncRNA TUC338-containing extracellular vesicles-induced supportive effects in LSCC aggressiveness were all abrogated by overexpressing miR-8485 and silencing CBX2. Collectively, this study is the first to identify a novel m6A/LncRNA TUC338/miR-8485/CBX2 axis in CAFs-EVs-mediated LSCC development, and to show its potential as a diagnostic biomarker for LSCC.

Traditional Banxia Xiexin decoction inhibits invasion, metastasis, and epithelial mesenchymal transition in gastric cancer by reducing lncRNA TUC338 expression

Background

Banxia Xiexin decoction (BXD) is a classic traditional Chinese medicine (TCM) formula clinically used to treat chronic gastritis, gastric ulcers, gastric cancer, and many other gastrointestinal diseases. Long noncoding RNAs (lncRNAs) have been shown to play an important role in maintaining the malignant phenotype of tumors. However, no relevant studies have shown whether Banxia Xiexin decoction regulates and controls lncRNA TUC338, and the effect of TUC338 on the regulation of gastric cancer invasion and metastasis remains unclear.

Purpose

To investigate the ability of the traditional Chinese medicine (TCM) Banxia Xiexin decoction (BXD) to inhibit the migration and invasion of human gastric cancer AGS cells by regulating the long noncoding RNA (lncRNA) TUC338.

Methods

UHPLC‒MS/MS was used to analyze the chemical components of BXD. MTT was performed to determine the effects of BXD on the proliferation of AGS cells. qRT‒PCR was used to determine the expression of lncRNA TUC338 in gastric cancer tissues, paracarcinoma tissues, AGS human gastric cancer cells and GES-1 normal gastric mucosa cells and to evaluate the effects of BXD on the expression of lncRNA TUC338 in AGS cells. Lentiviral transfection was used to establish human gastric cancer AGS cells with knocked down lncRNA TUC338 expression. The effects of lncRNA TUC338 knockdown on the migration and invasion of AGS cells were observed by a scratch assay and Transwell migration assay, respectively. Western blotting was performed to analyze the effects of lncRNA TUC338 knockdown on epithelial-to-mesenchymal transition (EMT) in AGS cells. We performed quality control on three batches of BXD. We used UHPLC‒MS/MS to control the quality of three random batches of BXD used throughout the study.

Results

Ninety-five chemical components were identified from the water extract of BXD, some of which have anticancer effects. The expression of TUC.338 in gastric cancer tissues was higher than that in para-carcinoma tissues. BXD inhibited the invasion and migration of gastric cancer cells by inhibiting the expression of lncRNA TUC338, which reduced EMT. After knockdown of lncRNA TUC338, the migration and invasion of AGS cells were reduced; the expression of the EMT-related protein E-cadherin was increased, and the expression of N-cadherin and vimentin was reduced.

Conclusions

The present results suggest that BXD has potential as an effective treatment for gastric cancer through the inhibition of lncRNA TUC338 expression.

LncRNA-miRNA axis in tumor progression and therapy response: An emphasis on molecular interactions and therapeutic interventions

Epigenetic factors are critical regulators of biological and pathological mechanisms and they could interact with different molecular pathways. Targeting epigenetic factors has been an idea approach in disease therapy, especially cancer. Accumulating evidence has highlighted function of long non-coding RNAs (lncRNAs) as epigenetic factors in cancer initiation and development and has focused on their association with downstream targets. microRNAs (miRNAs) are the most well-known targets of lncRNAs and present review focuses on lncRNA-miRNA axis in malignancy and therapy resistance of tumors. LncRNA-miRNA regulates cell death mechanisms such as apoptosis and autophagy in cancers. This axis affects tumor metastasis via regulating EMT and MMPs. Besides, lncRNA-miRNA axis determines sensitivity of tumor cells to chemotherapy, radiotherapy and immunotherapy. Based on the studies, lncRNAs can be affected by drugs and genetic tools in cancer therapy and this may affect expression level of miRNAs as their downstream targets, leading to cancer suppression/progression. LncRNAs have both tumor-promoting and tumor-suppressor functions in cancer and this unique function of lncRNAs has complicated their implication in tumor therapy. LncRNA-miRNA axis can also affect other signaling networks in cancer such as PI3K/Akt, STAT3, Wnt/β-catenin and EZH2 among others. Notably, lncRNA/miRNA axis can be considered as a signature for diagnosis and prognosis in cancers.