Higher content of microcystin-leucine-arginine promotes the survival of intrahepatic cholangiocarcinoma cells via regulating SET resulting in the poorer prognosis of patients

Microcystin-leucine arginine induces the proliferation of cholangiocytes and cholangiocarcinoma cells through the activation of the Wnt/β-catenin signaling pathway

Background

Microcystin-leucine arginine (MC-LR) is a cyanobacterial hepatotoxic toxin found in water sources worldwide, including in northeastern Thailand, where opisthorchiasis-associated cholangiocarcinoma (CCA) is most prevalent. MC-LR is a potential carcinogen; however, its involvement in liver fluke-associated CCA remains ambiguous. Here, we aimed to evaluate the effect of MC-LR on the progression of CCA via the Wnt/β-catenin pathway in vitro.

Methods

Cell division, migration, cell cycle transition, and MC-LR transporter expression were evaluated in vitro through MTT assay, wound healing assay, flow cytometry, and immunofluorescence staining, respectively. Following a 24-h treatment of cultured cells with 1, 10, 100, and 1,000 nM of MC-LR, the proliferative effect of MC-LR on the Wnt/β-catenin signaling pathway was investigated using immunoblotting and qRT-PCR analysis. Immunohistochemistry was used to determine β-catenin expression in CCA tissue compared to adjacent tissue.

Results

Human immortalized cholangiocyte cells (MMNK-1) and a human cell line established from opisthorchiasis-associated CCA (KKU-213B) expressed the MC-LR transporter and internalized MC-LR. Exposure to 10 nM and 100 nM of MC-LR notably enhanced cells division and migration in both cell lines (P < 0.05) and markedly elevated the percentage of S phase cells (P < 0.05). MC-LR elevated PP2A expression by activating the Wnt/β-catenin signaling pathway and suppressing phosphatase activity. Inhibition of the β-catenin destruction complex genes (Axin1 and APC) led to the upregulation of β-catenin and its downstream target genes (Cyclin D1 and c-Jun). Inhibition of Wnt/β-catenin signaling by MSAB confirmed these results. Additionally, β-catenin was significantly expressed in cancerous tissue compared to adjacent areas (P < 0.001).

Conclusions

Our findings suggest that MC-LR promotes cell proliferation and progression of CCA through Wnt/β-catenin pathway. Further evaluation using invivo experiments is needed to confirm this observation. This finding could promote health awareness regarding MC-LR intake and risk of CCA.

Microcystin-leucine-arginine promotes the development of gallbladder carcinoma via regulating ELAC2

Gallbladder carcinoma (GBC) is the most prevalent cancer of the bile tract, with unexpected GBC accounting for almost half of all GBC cases in some tertiary medical centers. Although the involvement of microcystin-leucine-arginine (MC-LR) in the development of intrahepatic cholangiocarcinoma has been established, there is a paucity of data regarding its association with GBC. The present study aims to investigate whether MC-LR level in the gallbladder of patients is associated with GBC development and, if so, to characterize the underlying mechanism in GBC cells. Our clinical data revealed that MC-LR level was significantly increased in GBC patients compared to patients with gallbladder stones only (P = 0.009). Moreover, our findings demonstrated that MC-LR could promote the proliferation and metastasis of human GBC cell lines. Furthermore, ELAC2 was identified as a critical mRNA involved in GBC progression through RNA sequencing. Collectively, our study suggests that MC-LR might be involved in the development of GBC by modulating the expression of ELAC2.

Role of the PP2A Pathway in Cholangiocarcinoma: State of the Art and Future Perspectives

Cholangiocarcinoma represents a heterogeneous disease at both a clinical and molecular level [...].

Microcystin-LR in Primary Liver Cancers: An Overview

The cyanobacterial blooms produced by eutrophic water bodies have become a serious environmental issue around the world. After cellular lysing or algaecide treatment, microcystins (MCs), which are regarded as the most frequently encountered cyanobacterial toxins in fresh water, are released into water. Among all the variants of MCs, MC-LR has been widely studied due to its severe hepatotoxicity. Since 1992, various studies have identified the important roles of MC-LR in the origin and progression of primary liver cancers (PLCs), although few reviews have focused on it. Therefore, this review aims to summarize the major achievements and shortcomings observed in the past few years. Based on the available literature, the mechanisms of how MC-LR induces or promotes PLCs are elucidated in this review. This review aims to enhance our understanding of the role that MC-LR plays in PLCs and provides a rational approach for future applications.

Higher content of microcystin-leucine-arginine promotes the survival of intrahepatic cholangiocarcinoma cells via regulating SET resulting in the poorer prognosis of patients

Background & Aims

Intrahepatic cholangiocarcinoma (ICC) has over the last 10 years become the focus of increasing concern largely due to its rising incidence and high mortality rates worldwide. Microcystin‐leucine‐arginine (MC‐LR) has been reported to be carcinogenic, but there are no data on the linkage between MC‐LR and ICC. This study aimed to explore whether the content levels of MC‐LR in the tumour tissues of ICC patients be associated with the prognosis and if so, to characterize the mechanism in ICC cells.

Methods

We conducted a retrospective study to evaluate the prognostic value of MC‐LR in ICC after resection. All patients were divided into two groups according to the content of MC‐LR in tumour via immunohistochemistry: low‐MC‐LR group (n = 28) and high‐MC‐LR group (n = 30).

Results

Multivariate analysis showed high‐MC‐LR level was the prognostic factor for OS and RFS after hepatectomy (P = .011 and .044). We demonstrated that MC‐LR could promote the survival of human ICC cell lines and SET was identified as an important mRNA in the progression via RNA array.

Conclusions

We provide evidence that MC‐LR was an independent prognostic factor for ICC in humans by modulating the expression of SET in human ICC cells.