Expression of CLIC1 as a potential biomarker for oral squamous cell carcinoma: a preliminary study

Intracellular chloride channel 1 and tumor

As the major intracellular anion, chloride plays an important role in maintaining intracellular and extracellular ion homeostasis, osmotic pressure, and cell volume. Intracellular chloride channel 1, which has the physiological role of forming membrane proteins in the lipid bilayer and playing ion channels, is a hot research topic in recent years. It has been found that CLIC1 does not only act as an ion channel but also participates in cell cycle regulation, apoptosis, and intracellular oxidation; thus, it participates in the proliferation, invasion, and migration of various tumor cells in various systems throughout the body. At the same time, CLIC1 is highly expressed in tumor cells and is associated with malignancy and a poor prognosis. This paper reviews the pathological mechanisms of CLIC1 in systemic diseases, which is important for the early diagnosis, treatment, and prognosis of systemic diseases associated with CLIC1 expression.

Chloride Intracellular Channel Protein 1 Expression and Angiogenic Profile of Liver Metastasis of Digestive Origin

Chloride intracellular channel 1 (CLIC1) is involved in cell migration and metastasis. The histological growth patterns of liver metastasis are as follows: desmoplastic (d-HGP), replacement (r-HGP), pushing (p-HGP), and mixed. The aim of this study was to evaluate the relation between HGP, angiogenesis, and CLIC1 expression. Materials and Methods: A total of 40 cases of primary tumors and their LM: d-HGP (12 cases), r-HGP (13 cases), and p-HGP (15 cases), were evaluated through simple and double immunostaining. CLIC1 assessment was conducted as follows: scores of 0 (less than 10% of positive cells), 1 (10-30%), 2 (30-50%), or 3 (more than 50%) were assigned. Heterogeneous CLIC1 expression was found. CLIC1 in primary tumors correlated with grade G for all cases of LM with a p-HGP (p = 0.004). The CLIC1 score for LMs with an r-HGP correlated with grade G of the corresponding primary tumor (p = 0.027). CLIC1 and CD34+/Ki67+ vessels (p = 0.006) correlated in primary tumors. CLIC1 in primary tumors correlated with CD34+/Ki67+ vessels of LMs with a d HGP (p = 0.024). Conclusions: The CLIC1 score may have prognostic value, mainly for LMs with a p-HGP and r-HGP, and therapeutic value for LMs with a d-HGP.

Chloride intracellular channel 1 promotes esophageal squamous cell carcinoma proliferation via mTOR signalling

OBJECTIVES

To investigate the clinical significance of Chloride Intracellular Channel 1 (CLIC1) expression in esophageal squamous cell carcinoma (ESCC) and its functional contribution and molecular mechanisms to the progression of ESCC.

METHODS

CLIC1 expression was analyzed by immunohistochemistry (IHC) in a cohort of 86 ESCC tissue specimens and paired normal adjacent esophageal tissues. Associations between clinicopathological features of ESCC and CLIC1 expression were determined. In vitro analyses examined CLIC1 expression in the ESCC cell lines KYSE150 and TE1 using RT-PCR and Western blotting. The downstream pathways of CLIC1 were detected by lentiviral shRNA knockdown and subsequent proteomic analyses. CLIC1 siRNA knockdown was performed in ESCC cell lines KYSE150 and TE1 and the functional effects of CLIC1 on the growth and proliferation of ESCC cells were evaluated combined with cell viability and colony formation assays; the mTOR signaling pathway-related proteins were detected by Western blotting based on the previous proteomic data.

RESULTS

CLIC1 expression was significantly increased in ex vivo ESCC tissues compared with corresponding normal tissues, and the up-regulation was associated with clinical tumor node metastasis (TNM) classifications. Knockdown of CLIC1 inhibited in vitro cell proliferation of ESCC cell lines KYSE150 and TE1. CLIC1 knockdown down-regulated the protein expression of p-mTOR and the downstream targets Rictor and p-4EBP1 in both KYSE150 and TE1 cell lines. And the CLIC1 knockdown induced inhibition of cell proliferation on ESCC cells could be rescued by mTOR overexpression.

CONCLUSIONS

CLIC1 expression increases during esophageal carcinogenesis and it may functionally contribute to the progression of ESCC through growth promotion effects by promoting the mTOR and downstream signaling pathway. CLIC1 therefore constitutes a candidate molecular biomarker of ESCC.

Chloride Intracellular Channel 1 is a Potential Biomarker for Breast Cancer

Purpose

Multiple reports have demonstrated that highly expressed chloride intracellular channel 1 (CLIC1) exists in a range of malignant tumors and is involved in proliferation, invasion, and migration of cancer cells. There are few studies on CLIC1 and breast cancer (BC). The purpose of this research was to evaluate the expression level of CLIC1 in BC and its impact on prognosis of BC patients.

Patients and Methods

Differences in CLIC1 expression levels in 25 pairs of BC and corresponding paracancerous specimens were tested by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot (WB). Immunohistochemistry (IHC) was performed to discuss the relevance between CLIC1 expression in BC tissue chips and clinicopathological parameters of BC patients. The effect of CLIC1 expression on patient prognosis was evaluated by Kaplan–Meier survival curve and Cox regression analysis. Receiver operating characteristic (ROC) curve assessed the diagnostic performance of CLIC1 for BC.

Results

The experimental results of qRT-PCR and WB demonstrated that CLIC1 was highly expressed in BC tissues. IHC results showed that overexpression of CLIC1 was strictly correlated with tumor size, TNM classification, pathological grade, lymph node metastasis and Ki67. Patients with lower CLIC1 expression had longer overall survival (OS) and progression-free survival (PFS). Cox regression analysis and ROC curve confirmed that CLIC1 could independently influence the prognosis of BC patients and might have diagnostic efficiency.

Conclusion

Overexpressed CLIC1 is closely related to the progression of BC and the poor prognosis of the patients, suggesting that it may act as a potential biological diagnostic index for BC.

CLIC1 Drives Angiogenesis in Hepatocellular Carcinoma by Modulating VEGFA

Background: Chloride intracellular channel 1 (CLIC1) is upregulated in hepatocellular carcinoma (HCC). The present study aimed to investigate the role of CLIC1 in HCC angiogenesis. Materials and Methods: Immunohistochemistry (IHC) was used to test the expression of CLIC1 and CD34 in 67 pairs of HCC and paracarcinoma tissues. The prognosis data of the patients were used to analyze the clinical relevance of CLIC1. We built a coculture system of HCC cells and endothelial cells to explore the migration of endothelial cells. Conditioned media (CMs) from HCC cells was then collected to assess endothelial cell migration. Experiments were then conducted to confirm the relationship between CLIC1 and angiogenesis in a subcutaneous tumor model. Results: CLIC1 expression was higher in HCC tumor tissues than in paracarcinoma tissues. Patients with increased CLIC1 expression showed a higher microvascular density (MVD; P = .013). Kaplan-Meier curves indicated that patients with lower expression of CLIC1 had better overall survival (P < .001) and recurrence-free survival (P = .046). Vascular endothelial growth factor A (VEGFA) in CMs from CLIC1-knockdown cells was lower than in the control group, while VEGFA in CMs from CLIC1 overexpression cells was higher than in the control group. CMs from CLIC1 overexpression cell lines promote the in vitro migration of EA.hy926 cells. Meanwhile, adding Bevacizumab to CMs from CLIC1 overexpression cells significantly inhibited this migration. The growth of xenograft tumors derived from CLIC1-knockdown Huh7 cells was restrained compared with the control group (P < .001). IHC staining showed MVD was higher in tumors with CLIC1 overexpression. Conclusion: CLIC1 is a promising biomarker for predicting the prognosis of HCC patients, and expression of CLIC1 correlates with angiogenesis in HCC through regulating VEGFA.

Matrisome provides a supportive microenvironment for oral squamous cell carcinoma progression

Oral squamous cell carcinoma (OSCC) is a common pernicious tumor in the head and neck regions. However, the function of tumor extracellular matrix (ECM) has not been elucidated. A tissue engineering method was applied for remodeling ECM through decellularization. The cellular components were removed, and the biological composition was mostly preserved. Proteomics was performed to analyze the characterization between normal and tumor ECM. According to LC-MS/MS results, 26 proteins just showed in tumor ECM, and 14 proteins only showed in late-stage tumor ECM. KEGG pathway analysis showed that most variant proteins were linked to metabolic regulation and tumor immunity (such as SCC-Ag1, LOX). To affirm the influence of tumor ECM on the progression of OSCC, tumor cells and macrophages were co-cultured with ECM scaffold. Marked differences in proliferation, apoptosis, and migration of OSCC cells were observed between tumor and normal ECM. Tumor ECM polarized macrophages towards an anti-inflammatory phenotype (higher IL-10 and CD68, and relatively lower CD86 and IL1-β). Collectively, these findings suggest that tumor ECM served as a permissive role in OSCC progression. SIGNIFICANCE: The variation between OSCC ECM and normal ECM confirm tumor ECM plays a significant role in OSCC deterioration, which is conducive to exploring the occurrence and progression mechanisms of OSCC, and further improving the curative effect of this disease.

Characterization of Cancer Stem Cell Characteristics and Development of a Prognostic Stemness Index Cell-Related Signature in Oral Squamous Cell Carcinoma

Objective

Cancer stem cells (CSCs) with self-renewal and plasticity contribute to tumor initiation and progression. This study developed an mRNA expression-based stemness index- (mRNAsi-) associated signature and validated biological functions of stem cell-related genes in oral squamous cell carcinoma (OSCC).

Methods

Here, mRNAsi was measured for OSCC samples from TCGA cohort, and prognosis and tumor microenvironment (stromal/immune scores, tumor purity) in high- and low-mRNAsi samples were evaluated with survival analyses and ESTIMATE algorithm. Based on prognostic mRNAsi-related genes, a risk score model was constructed by the LASSO method. The predictive accuracy was evaluated by uni- and multivariate Cox analyses and ROC curves. Among the genes in the model, the functions of H2AFZ on proliferation, apoptosis, invasion, and EMT were investigated in OSCC cells.

Results

High mRNAsi was distinctly associated with undesirable prognosis, increased stromal and immune scores, and lowered tumor purity. The mRNAsi-associated signature containing 11 genes was developed, and high-risk score was distinctly related to poor survival outcomes. Moreover, this signature was an independent and robust risk factor. H2AFZ upregulation significantly enhanced proliferative and invasive capacities and facilitated EMT as well as lowered apoptotic levels in Cal-27 and HSC-3 cells.

Conclusion

Our study characterized cancer stem cell characteristics that were closely related to tumor microenvironment and developed a stemness index cell-related signature that could assist prognosis prediction and risk stratification for OSCC. H2AFZ could become a potential therapeutic target against OSCC.

Novel Therapeutic Approaches of Ion Channels and Transporters in Cancer

The expression and function of many ion channels and transporters in cancer cells display major differences in comparison to those from healthy cells. These differences provide the cancer cells with advantages for tumor development. Accordingly, targeting ion channels and transporters have beneficial anticancer effects including inhibition of cancer cell proliferation, migration, invasion, metastasis, tumor vascularization, and chemotherapy resistance, as well as promoting apoptosis. Some of the molecular mechanisms associating ion channels and transporters with cancer include the participation of oxidative stress, immune response, metabolic pathways, drug synergism, as well as noncanonical functions of ion channels. This diversity of mechanisms offers an exciting possibility to suggest novel and more effective therapeutic approaches to fight cancer. Here, we review and discuss most of the current knowledge suggesting novel therapeutic approaches for cancer therapy targeting ion channels and transporters. The role and regulation of ion channels and transporters in cancer provide a plethora of exceptional opportunities in drug design, as well as novel and promising therapeutic approaches that may be used for the benefit of cancer patients.

Intracellular Chloride Ion Channel Protein-1 Expression in Clear Cell Renal Cell Carcinoma

BACKGROUND/AIM

Chloride intracellular channel 1 (CLIC1) represents a promising target for personalized therapy. Our aim was to assess CLIC1 expression in clear cell renal cell carcinoma (cc RCC) and identify its possible prognostic role.

MATERIALS AND METHODS

Fifty cases of cc RCC were evaluated and selected for immunohistochemistry. CLIC1 expression was correlated with tumor grade, invasion and heterogeneity.

RESULTS

A total of 87.5% of the cases were CLIC1 positive, with either a homogeneous (31.42%) or a heterogeneous (68.57%) pattern. Low, mild and strong CLIC1 expressing tumors were defined based on nuclear (N), cytoplasmic (C), membrane (M) or combinations of them (NC, NM, CM, NCM) in terms of CLIC1 distribution. A significant correlation was found between tumor grade and percent of positive tumor cells (p=0.017). For G3 tumors, CLIC1 cytoplasmic expression was strongly correlated with high expression status (p=0.025) and tumor heterogeneity (p=0.004). CLIC1 expression was also correlated with metastasis (p=0.046).

CONCLUSION

We defined four cc RCC groups depending on G, CLIC1 expression and pattern: i) G3/NM/low CLIC1⁺, ii) G2/CM/mild CLIC1⁺ iii) G1 or G2/NM or CM /high CLIC1⁺, and iv) G2/M /high CLIC1^.

CLIC1 promotes the progression of oral squamous cell carcinoma via integrins/ERK pathways

Chloride intracellular channel 1 (CLIC1), a member of the chloride channel protein family, acts as a promoter in many malignancies, but its role in oral cancer remains unclear. Hence, this research aimed to explore the effects of CLIC1 on the progression of oral cancer cells in vitro, and we assessed its role in cell proliferation, apoptosis, migration, invasion, angiogenesis, and chemosensitivity to cisplatin and possible signaling pathways. The results demonstrated that CLIC1 depletion inhibited the proliferation, invasion, migration and angiogenesis of oral squamous cell carcinoma (OSCC) cells in vitro, but promoted cell apoptosis and increased the drug susceptibility to cisplatin. In contrast, CLIC1 upregulation was positively correlated with cell proliferation, invasion and migration and angiogenesis. Mechanistically, CLIC1 silencing decreased the levels of ITGαv, ITGβ1, p-ERK, vimentin, MMP2 and MMP9, and increased the levels of p-p38, E-cadherin, caspase3 and caspase9. CLIC1 overexpression enhanced the ITGαv, ITGβ1, p-ERK, vimentin, MMP2 and MMP9 levels and decreased E-cadherin expression. Overall, these results indicated that CLIC1 promotes the progression of OSCC, and we speculated that its potential mechanism may be related to the regulation of ITGαv and ITGβ1, which led to activation of the MAPK/ERK and MAPK/p38 signal pathways.