Chemokine (C-C motif) ligand 18/membrane-associated 3/forkhead box O1 axis promotes the proliferation, migration, and invasion of intrahepatic cholangiocarcinoma

IRG1 restrains M2 macrophage polarization and suppresses intrahepatic cholangiocarcinoma progression via the CCL18/STAT3 pathway

Intrahepatic cholangiocarcinoma (ICC) is a highly malignant and aggressive cancer whose incidence and mortality continue to increase, whereas its prognosis remains dismal. Tumor-associated macrophages (TAMs) promote malignant progression and immune microenvironment remodeling through direct contact and secreted mediators. Targeting TAMs has emerged as a promising strategy for ICC treatment. Here, we revealed the potential regulatory function of immune responsive gene 1 (IRG1) in macrophage polarization. We found that IRG1 expression remained at a low level in M2 macrophages. IRG1 overexpression can restrain macrophages from polarizing to the M2 type, which results in inhibition of the proliferation, invasion, and migration of ICC, whereas IRG1 knockdown exerts the opposite effects. Mechanistically, IRG1 inhibited the tumor-promoting chemokine CCL18 and thus suppressed ICC progression by regulating STAT3 phosphorylation. The intervention of IRG1 expression in TAMs may serve as a potential therapeutic target for delaying ICC progression.

Exosome-Delivered EGFR Induced by Acidic Bile Salts Regulates Macrophage M2 Polarization to Promote Esophageal Adenocarcinoma Cell Proliferation

Purpose

Chronic gastroesophageal reflux disease (GERD) causes the abnormal reflux of acid and bile salts, which would induce Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). EGFR, as one of main components of the exosome, plays an important role in cancer progression. Here, we investigated the role of acidic bile salts (ABS)-induced exosomal EGFR in EAC cell proliferation.

Methods

Electronic microscopic examination and Western blot were used to identify exosomes. Western blot, siRNA transfection, enzyme-linked immunosorbent assay, qRT-PCR, cell viability detection, mouse xenograft tumor models, and immunohistochemical staining were performed to study the function of ABS-induced exosomal EGFR in cell proliferation.

Results

We found that ABS improved the exosomal EGFR level of normal human esophageal epithelial cells, BE cells, and BE-associated adenocarcinoma cells. The results were confirmed in the serum-derived exosomes from healthy persons and patients suffering from GERD, BE with or without GERD, and EAC with or without GERD. Moreover, cell line-derived exosomal EGFR was found to promote macrophage M2 polarization through the PI3K-AKT pathway. The co-incubation medium of macrophages and exosomes improved cell proliferation and tumor growth, which depended on the exosomal EGFR level. CCL18 was identified as the most effective component of the co-incubation medium to promote EAC cell proliferation by binding to its receptor PITPNM3 in vitro and in vivo.

Conclusion

Our findings demonstrate that ABS-induced exosomal EGFR regulates macrophage M2 polarization to promote EAC proliferation. This study provides an important insight into the role of ABS in EAC development.

Long non-coding RNA MIR600HG as a ceRNA inhibits the pancreatic cancer progression through regulating the miR-1197/PITPNM3 axis

Objective

Pancreatic cancer (PC) is considered to be a highly malignant cancer with poor prognosis. Long non-coding RNAs (lncRNAs) is the potential factor to predict cancer prognosis. The effect of MIR600HG in PC needs to be further studied. Our work mainly focused on the importance of MIR600HG for PC prognosis and its underlying molecular mechanism of regulating PC progression.

Methods

Data set was acquired from TCGA database to find differentially expressed genes and prognostic significance of MIR600HG in PC, and to construct the MIR600HG competitive endogenous RNA (ceRNA). Clinical specimens were collected to prove the analysis results. Vector over-expressed MIR600HG was transfected to study the roles of MIR600HG in proliferation, apoptosis, invasion and migration. The methods of CCK-8, flow cytometry, Transwell and scratch assays were all used in order to explore the apoptosis, migration and invasion. We evaluated the proliferation-related genes (PCNA, CyclinD1 and P27), as well as invasion and migration-related genes such as MMP-9, MMP-7 and ICAM-1. The transcriptional regulation between MIR600HG and miR-1197/PITPNM3 axis was determined with luciferase reporter assays.

Results

In present study, MIR600HG was dropped in both PC tissues and cells, and the down-regulated MIR600HG was closely related to the poor clinical outcomes in PC patients. MIR600HG could inhibit proliferation, migration and invasion in PC cells. We also investigated whether MIR600HG acting as a sponge of microRNA-1197 (miR-1197) and miR-1197 acting on PITPNM3. We found the positive association between MIR600HG and PITPNM3, as well as the negative association of miR-1197 and MIR600HG (or PITPNM3). Moreover, PITPNM3 mRNA and protein expression saw a simultaneous increase after the MIR600HG-overexpression (MIR600HG-OE), but this result partially diminished in MIR600HG-OE cells and miR-1197 mimics.

Conclusions

Our study explored the anticancer action of MIR600HG in PC by regulating miR-1197 to increase the expression of PITPNM3, which might help the diagnosis and therapy of PC.

miR-552 promotes the proliferation and metastasis of intrahepatic cholangiocarcinoma by targeting FOXO1

Intrahepatic cholangiocarcinoma (ICC) is a relatively rare but highly malignant cancer. Few effective systemic targeted therapies are available for patients with unresectable ICC, but there exists an urgent need to explore mechanisms underlying the initiation and progression of ICC. MicroRNA (miRNA) plays vital roles in the initiation, progression, and drug resistance of different cancers. Recently, the biological function of a novel miRNA, miR-552, has been widely analyzed in hepatocellular carcinoma and colorectal, cervical, gastric, and other cancers. However, its role in ICC has not yet been elucidated. In this study, we found that miR-552 expression was upregulated in ICC and that miR-552 predicted poor prognosis. Using functional studies, we found that miR-552 enhanced the proliferation and invasion ability of ICC cells. Mechanistic research identified that forkhead box O1 (FOXO1) is the target of miR-552 in ICC. Moreover, the combined panels of miR-552 and FOXO1 exhibited a better prognostic value for ICC patients than did miR-552 alone. In conclusion, these findings demonstrated that the miR-552/FOXO1 axis drove ICC progression, further suggesting that targeting this axis could be a novel therapeutic strategy for ICC.

Redox Dysregulation in the Tumor Microenvironment Contributes to Cancer Metastasis

Significance: Redox dysregulation under pathological conditions results in excessive reactive oxygen species (ROS) accumulation, leading to oxidative stress and cellular oxidative damage. ROS function as a double-edged sword to modulate various types of cancer development and survival. Recent Advances: Emerging evidence has underlined that ROS impact the behavior of both cancer cells and tumor-associated stromal cells in the tumor microenvironment (TME), and these cells have developed complex systems to adapt to high ROS environments during cancer progression. Critical Issues: In this review, we integrated current progress regarding the impact of ROS on cancer cells and tumor-associated stromal cells in the TME and summarized how ROS production influences cancer cell behaviors. Then, we summarized the distinct effects of ROS during different stages of tumor metastasis. Finally, we discussed potential therapeutic strategies for modulating ROS for the treatment of cancer metastasis. Future Directions: Targeting the ROS regulation during cancer metastasis will provide important insights into the design of effective single or combinatorial cancer therapeutic strategies. Well-designed preclinical studies and clinical trials are urgently needed to understand the complex regulatory systems of ROS in the TME. Antioxid. Redox Signal. 39, 472-490.