Long noncoding RNA LINC00473 drives the progression of pancreatic cancer via upregulating programmed death-ligand 1 by sponging microRNA-195-5p.

Pancreatic cancer (PC) is a great health burden to patients owing to its poor overall survival rate. Long noncoding RNAs (lncRNAs) interact with microRNAs (miRs) to participate in tumorigenesis. Therefore, we aim to uncover the role and related mechanism of LINC00473 in PC through the modulation of miR-195-5p and programmed death-ligand 1 (PD-L1). Increased LINC00473 and PD-L1 but declined miR-195-5p were determined in PC tissues and cell lines, and it was found that LINC00473 mainly situated in the cytoplasm. Also, miR-195-5p was verified to bind with both LINC00473 and PD-L1. Next, with the aim to examine the ability of LINC00473, miR-195-5p, and PD-L1 on the PC progression, the expression of LINC00473, miR-195-5p and PD-L1 were altered with mimics, inhibitors, overexpression vectors or siRNAs in PC cells and cocultured CD8+ T cells. It was demonstrated that LINC00473 sponged miR-195-5p to upregulate PD-L1 expression. More important, the obtained results revealed that LINC00473 silencing or miR-195-5p upregulation elevated the expression of Bcl-2 associated X protein (Bax), interferon (IFN)-γ, and interleukin (IL)-4 but reduced the expression of B-cell lymphoma-2 (Bcl-2), matrix metalloproteinase (MMP)-2, MMP-9, and IL-10, thus inducing the enhancement of the apoptosis as along with the inhibition of proliferation, invasion, and migration of the PC cells. LINC00473 silencing or miR-195-5p elevation activated the CD8+ T cells. Taken together, LINC00473 silencing blocked the PC progression through enhancing miR-195-5p-targeted downregulation of PD-L1. This finding offers new therapeutic options for treating this devastating disease.

Zhou WY ，Zhang MM ，Liu C ，Kang Y ，Wang JO ，Yang XH ... -  《-》

miR-194-5p down-regulates tumor cell PD-L1 expression and promotes anti-tumor immunity in pancreatic cancer.

Pancreatic cancer is a highly malignant cancer of the digestive tract. Studies have shown that in some types of cancer, a high level of microRNA-194-5p (miR-194-5p) is beneficial for controlling tumor progression, while in other cancers it plays a completely opposite role. However, how miR-194-5p affects anti-tumor immunity of pancreatic cancer remains unclear. In this study, we found that high expression of miR-194-5p in human pancreatic cancer patients is associated with a better survival rate, while increased expression of programmed cell death ligand 1 (PD-L1) in human pancreatic cancer patients is associated with a worse survival rate. In pancreatic cancer, the expression level of PD-L1 is negatively correlated with the expression level of miR-194-5p, and we identified that PD-L1 was target gene of miR-194-5p. In addition, we found that overexpression of miR-194-5p inhibited the migration, invasion and proliferation of pancreatic cancer cells in vitro. The orthotopic mouse model of pancreatic cancer shown that miR-194-5p suppressed the progression of pancreatic cancer, promoted the infiltration of CD8+ T cells in tumor immune microenvironments, and enhanced the IFN-γ production of CD8+ T cells. Consistently, the co-culture experiments showed that overexpression of miR-194-5p in tumor cell enhanced IFN-γ production by CD8+ T cells. In conclusion, miR-194-5p may serve as a novel immunotherapeutic target for pancreatic ductal adenocarcinoma (PDAC) by inhibiting the expression of PD-L1, and play important roles in inhibiting the progression of pancreatic cancer and boosting the anti-tumor effect of CD8+ T cells.

Wang C ，Li X ，Zhang L ，Chen Y ，Dong R ，Zhang J ，Zhao J ，Guo X ，Yang G ，Li Y ，Gu C ，Xi Q ，Zhang R ... -  《-》

Silencing of long noncoding RNA LINC00958 prevents tumor initiation of pancreatic cancer by acting as a sponge of microRNA-330-5p to down-regulate PAX8.

Pancreatic cancer (PC) represents a relatively rare but severe malignancy worldwide. Accumulated studies have emphasized the potential of long noncoding RNA (lncRNA) as therapeutic strategies for several human cancers. Thus, we aimed to investigate whether a novel non-coding RNA regulatory circuitry involved in PC. Aberrantly expressed lncRNAs and mRNAs were screened out of microarray database. Following the determination of RNA expression, PANC-1 and BxPC-3 PC cells were adopted, after which the expression of miR-330-5p, PAX8 and LINC00958 were subsequently altered. RNA crosstalk was validated by dual-luciferase reporter gene assay. In order to detect whether LINC00958 could act as ceRNA to competitively sponge miR-330-5p and regulate PAX8, subcellular location of LINC00958 and interaction between LINC00958 and miR-330-5p were measured by FISH and RNA pull down respectively. The epithelial mesenchymal transition (EMT) process, cell invasion, and tumor growth were determined in vitro and in vivo. LINC00958 and PAX8 were up-regulated, while miR-330-5p was down-regulated during PC. LINC00958 mainly expressed in the cytoplasm and LINC00958 competitively sponged miR-330-5p. Upregulated miR-330-5p or downregulated PAX8 inhibited the EMT process as well as the invasion and metastasis ability of the PC cells. Moreover, the results indicated that miR-330-5p negatively targeted PAX8, and LINC00958 ultimately showcasing its ability to bind to miR-330-5p through its interaction with AGO2. Therefore, silencing of LINC00958 may bind to miR-330-5p to inhibit PAX8 in a competitive fashion, thereby preventing the progression of PC.

Chen S ，Chen JZ ，Zhang JQ ，Chen HX ，Qiu FN ，Yan ML ，Tian YF ，Peng CH ，Shen BY ，Chen YL ，Wang YD ... -  《-》

LncRNA HCP5 Regulates Pancreatic Cancer Progression by miR-140-5p/CDK8 Axis.

Yuan B ，Guan Q ，Yan T ，Zhang X ，Xu W ，Li J ... -  《-》

MicroRNA-93-5p expression in tumor tissue and its tumor suppressor function via targeting programmed death ligand-1 in colorectal cancer.

This work aimed to investigate miR-93-5p expression in tumor tissue and its in vitro effects in colorectal cancer (CRC) by targeting programmed death ligand-1 (PD-L1). MiR-93-5p and PD-L1 expression was detected in CRC and adjacent normal tissues by quantitative real-time polymerase chain reaction and immunohistochemistry. The correlation between miR-93-5p and PD-L1 was validated by a dual-luciferase reporter assay. HCT116 and SW480 cells were divided into blank, miR-NC, miR-93-5p mimics, miR-93-5p inhibitor, PD-L1 small interfering RNA (siRNA) and miR-93-5p inhibitor + PD-L1 siRNA groups, and wound-healing and transwell assays were performed to detect cell migration and invasion, respectively. Protein expression was measured by western blotting. The secretion of cytokines was detected in the CRC cell/T coculture models. MiR-93-5p was downregulated in CRC tissues with upregulated PD-L1. In PD-L1-negative patients, miR-93-5p expression was increased compared with that in PD-L1-positive patients. MiR-93-5p and PD-L1 expression levels were associated with the tumor differentiation, lymphatic metastasis, TNM, Duke's stage, and prognosis of CRC. PD-L1 siRNA weakened the migration and invasion abilities via decreased expression of matrix metalloproteinase-1 (MMP-1), -2, and -9, and these effects were abolished by the miR-93-5p inhibitor. Additionally, anti-PD-L1 upregulated the expressions of interleukin-2 (IL-2), tumor necrosis factor-α (TNF-α), and interferon γ (IFN-γ) in the coculture of T cells with CRC cells, but downregulated the expressions of IL-1β, IL-10, and TGF-β. However, these changes were partially reversed by miR-93-5p inhibition. miR-93-5p is expected to be a novel target for CRC treatment since it decreases the migration and invasion, as well as the immune evasion, of CRC cells via targeting PD-L1.

Chen YL ，Wang GX ，Lin BA ，Huang JS ... -  《-》