CXCL1-ICAM-1軸在肝細胞癌中的作用：腫瘤細胞遷移的關鍵推動因子及潛在治療靶點

Abstract

背景 肝細胞癌(Hepatocellular Carcinoma, HCC)是全球癌症相關死亡的主要原因之一，主要由於其高度侵襲性、高轉移潛能以及缺乏早期檢測標誌物。儘管外科手術、標靶治療和免疫療法不斷進步，HCC患者的總體存活率仍然偏低。肺部、淋巴結和門靜脈的轉移是導致治療失敗和預後不良的主要因素。趨化因子(C-X-C Motif Chemokine Ligand 1, CXCL1)在免疫調節和腫瘤進展中發揮關鍵作用，並透過與其受體(C-X-C Motif Chemokine Receptor 2, CXCR2)及下游訊號通路的互動促進癌細胞的轉移。先前的研究顯示，CXCL1可透過活化CXCR2 /Focal Adhesion Kinase (FAK) /Phosphatidylinositol-3-Kinase (PI3K) /Akt /Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB)訊號級聯反應，促進骨肉瘤中血管細胞黏附分子1(Vascular Cell Adhesion Molecule-1, VCAM-1)的表達，進而促使肺部轉移。類似地，在肝細胞癌(HCC)中，CXCL1亦被證實能透過上調細胞間黏附分子1(Intercellular Adhesion Molecule-1, ICAM-1)來增強癌細胞的遷移能力。值得注意的是，ICAM-1作為免疫球蛋白超家族的一員，在腫瘤–內皮細胞互動及促進免疫逃逸過程中扮演了關鍵角色。此外，除了蛋白質層級的調控外，微小核糖核酸(Micro Ribonucleic Acid, miRNA)亦逐漸被認為是ICAM-1表達的重要調節因子，進而影響腫瘤的轉移潛能。其中，miR-30b-5p被鑑定為ICAM-1的負向調控者，而其表達在接受CXCL1刺激後顯著下調，提示可能存在一種進一步增強ICAM-1介導之腫瘤進展的反饋機制。綜合上述發現，CXCL1–ICAM-1軸在線上癌轉移中扮演了關鍵角色，並突顯了針對CXCL1、ICAM-1及其相關訊號路徑進行治療干預，可能作為抑制腫瘤進展及改善臨床預後的潛在策略。

研究目標 本研究旨在探討HCC轉移的分子機制，重點關注CXCL1在炎症及腫瘤進展中的作用。我們希望釐清CXCL1如何調控ICAM-1的表達，並進一步研究其與microRNA-30b-5p(miR-30b-5p)及PI3K/Akt/NF-κB訊號通路之間的關聯。

研究方法 我們透過實驗分析CXCL1對HCC細胞遷移與轉移的影響，並測量不同轉移潛能HCC細胞株與組織樣本中的CXCL1表達量。透過西方點墨法(Western blot)與免疫螢光染色(Immunofluorescence)評估CXCL1對ICAM-1表達的影響。此外，使用藥理抑制劑與小分子干擾核糖核酸(Small Interfering Ribonucleic Acid, siRNA)介導的基因靜默技術，探討PI3K/Akt/NF-κB訊號通路的參與機制。此外，透過定量聚合酶連鎖反應(Quantitative Polymerase Chain Reaction, qPCR)與螢光素酶報導基因分析(luciferase reporter assay)，研究CXCL1對miR-30b-5p的調控作用。

研究結果 本研究結果顯示，CXCL1可透過PI3K/Akt/NF-κB訊號通路上調ICAM-1表達，在HCC晚期組織中，CXCL1表達量升高與較差的預後和高轉移風險密切相關。此外，CXCL1促進ICAM-1表達後，HCC細胞的遷移能力顯著增強，進一步證實其在腫瘤轉移中的關鍵作用。同時，我們發現CXCL1可下調miR-30b-5p，而miR-30b-5p原本可抑制ICAM-1表達。miR-30b-5p的喪失導致ICAM-1表達進一步升高，顯示CXCL1可能透過破壞miRNA調控機制來促進HCC轉移。

結論 本研究揭示了CXCL1–ICAM-1軸在HCC轉移中的關鍵作用，該途徑受PI3K/Akt/NF-κB訊號調控，並受到miR-30b-5p的影響。CXCL1可作為抑制HCC轉移的重要治療標的，未來應著重於發展CXCL1的標靶抑制劑PI3K/Akt/NF-κB，以及恢復miR-30b-5p表達的策略。此外，將這些新興治療方式與現有療法結合，可能有助於降低HCC轉移風險，並提升患者的存活率及治療效果。

Background Hepatocellular Carcinoma (HCC) is a leading cause of cancer-related mortality worldwide, primarily due to its aggressive progression, high metastatic potential, and lack of early detection biomarkers. Despite advances in surgical techniques, targeted therapies, and immunotherapies, the overall survival rate for HCC patients remains dismal. Metastasis, particularly to the lungs, lymph nodes, and portal vein, is a primary factor contributing to treatment failure and poor prognosis. C-X-C Motif Chemokine Ligand 1 (CXCL1) , a chemokine involved in immune regulation and tumor progression, has been identified as a key player in cancer metastasis through its interaction with C-X-C Motif Chemokine Receptor 2 (CXCR2) and downstream signaling pathways. Previous investigations have demonstrated that CXCL1 facilitates pulmonary metastasis in osteosarcoma by upregulating Vascular Cell Adhesion Molecule-1 (VCAM-1) expression through activation of the CXCR2 /Focal Adhesion Kinase (FAK) /Phosphatidylinositol-3-Kinase (PI3K) /Akt /Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling cascade. Similarly, in HCC, CXCL1 has been shown to enhance cancer cell migration via the upregulation of Intercellular Adhesion Molecule-1 (ICAM-1). Notably, ICAM-1, a member of the immunoglobulin superfamily, plays a critical role in mediating tumor–endothelial cell interactions and contributes substantially to immune evasion. Moreover, in addition to protein-level regulation, Micro Ribonucleic Acids (miRNAs) have emerged as key modulators of ICAM-1 expression, thereby influencing metastatic potential. In particular, microRNA-30b-5p (miR-30b-5p) has been identified as a negative regulator of ICAM-1, and its expression was found to be significantly downregulated following CXCL1 stimulation, suggesting a potential feedback mechanism that amplifies ICAM-1-mediated tumor progression. Collectively, these findings underscore the pivotal role of the CXCL1–ICAM-1 axis in tumor metastasis and highlight the therapeutic potential of targeting CXCL1, ICAM-1, and their associated signaling pathways to inhibit cancer progression and improve clinical outcomes.

Objective This study seeks to investigate the molecular mechanisms responsible for HCC metastasis, focusing on the chemokine CXCL1, which is involved in inflammation and tumor progression. Specifically, we aim to understand the role of CXCL1 in regulating the expression of ICAM-1 and its interaction with miR-30b-5p and the PI3K/Akt/NF-κB signaling pathway.

Methods Our experiments were conducted to analyze the impact of CXCL1 on HCC cell migration and metastasis. CXCL1 levels were measured in HCC tissue samples and cell lines with varying metastatic potential. The effects of CXCL1 on ICAM-1 expression were assessed using Western blotting and immunofluorescence techniques. The involvement of the PI3K/Akt/NF-κB signaling pathway was investigated through pharmacological inhibitors and siRNA-mediated knockdown. Additionally, the regulation of miR-30b-5p by CXCL1 was analyzed using quantitative PCR (qPCR) and luciferase reporter assays.

Results Our study demonstrated that CXCL1 upregulates ICAM-1 expression in HCC cells through the PI3K/Akt/NF-κB signaling pathway. Elevated CXCL1 expression in advanced-stage HCC tissues was associated with poor prognosis and metastasis. CXCL1-induced ICAM-1 expression was shown to enhance HCC cell migration, reinforcing its role in promoting metastatic dissemination. Furthermore, CXCL1 downregulated miR-30b-5p, which normally suppresses ICAM-1 expression. The loss of miR-30b-5p led to a further increase in ICAM-1 levels, suggesting that CXCL1 promotes HCC metastasis by disrupting this miRNA-mediated regulatory mechanism.

Conclusion Our findings reveal that the CXCL1-ICAM-1 axis is a critical driver of HCC metastasis, facilitated by the PI3K/Akt/NF-κB signaling pathway and miR-30b-5p downregulation. This pathway highlights CXCL1 as a potential therapeutic target for inhibiting HCC metastasis. Future therapeutic strategies should focus on developing targeted inhibitors for CXCL1, the PI3K/Akt/NF-κB pathway, and restoring miR-30b-5p expression. Moreover, combining these approaches with existing treatments may improve patient outcomes and survival rates by reducing HCC metastasis and improving the effectiveness of current therapies.