| 摘要: | 背景：免疫系統和腫瘤細胞之間的相互作用是肺癌進展和產生治療抗藥性的關鍵。 EGFR（表皮生長因子受體）訊號傳導的擾動有可能通過上調各種免疫抑製劑（包括檢查點、免疫抑制細胞和細胞因子）來創造免疫抑制環境。肝素結合表皮生長因子類生長因子(HB-EGF) 的是一種EGFR 配體和趨化因子，其表達升高與組織學分級較高、預後較差和總體存活率降低相關。然而，HB-EGF 在腫瘤微環境 (TME) 內免疫細胞積累中的確切作用仍未完全了解。
方法：我們利用Gene Expression Omnibus 資料集分析來評估在非小細胞肺癌中HB-EGF的表現與臨床相關性。以公開可用的單細胞 RNA 定序分析資料來確認 HB-EGF在正常肺組織和肺癌樣本中的表現。 此外，我們使用 TIMER 研究 HB-EGF 基因表現與癌症免疫細胞浸潤的相關性，並使用 TCGA資料集以GSEA 和 ClueGo進行功能路徑分析。為了驗證 HB-EGF 的趨化作用，我們使用單核球細胞和巨噬細胞進行了細胞遷移實驗，並在M2巨噬細胞和肺癌細胞之間進行共培養實驗。以免疫組織化學染色法測定肺組織中 HB-EGF蛋白表達和 M1/M2 巨噬細胞的聚集。
結果：我們發現HB-EGF基因的高度表現與肺腺癌的總體生存率低下顯著相關，但與肺鱗狀細胞癌無關。 在 肺腺癌中HB-EGF 表現與單核細胞、巨噬細胞、中性粒細胞和樹突狀細胞的浸潤呈正相關，而在 LUSC中未觀察到這種相關性。在腫瘤細胞以及單核細胞、巨噬細胞和樹突細胞中檢測到 HB-EGF 的上調。以功能路徑分析顯示 HB-EGF表現多與癌症標記有關。值得注意的是，體外研究證實 HB-EGF 可誘導單核細胞和巨噬細胞的遷移，並有助於共培養實驗中癌細胞的生長和遷移。 此外，與鄰近組織相比，在肺腺癌腫瘤中HB-EGF表現較高並與 M2巨噬細胞的表現型呈正相關。
結論：在肺腺癌中HB-EGF的高度表現與較差的存活結果密切相關。肺腺癌細胞分泌的 HB-EGF可能有助於腫瘤微環境內免疫抑制細胞的募集。總之，HB-EGF 代表抑制肺癌進展的潛在治療靶點，特別是在肺腺癌患者中。
Background: The interaction between the immune system and tumor cells is pivotal in driving the progression and treatment resistance of lung cancer. Perturbations in EGFR (epidermal growth factor receptor) signaling has the potential to create an immune-suppressed environment by upregulating various immune inhibitors, including checkpoints, immunosuppressive cells, and cytokines. Elevated expression of heparin-binding EGF-like growth factor (HB-EGF), an EGFR ligand associated with higher histology grading, poorer prognosis, and reduced overall survival, serves as a chemotactic factor. However, the precise role of HB-EGF in immune cell accumulation within the tumor microenvironment (TME) remains incompletely understood.
Methods: We evaluated the clinical associations of HB-EGF expression in non-small-cell lung carcinoma by analyzing Gene Expression Omnibus datasets. Publicly available single-cell RNA sequencing data were utilized to examine the expression of HB-EGF in normal lung tissue and lung cancer samples. Additionally, we investigated the correlations between HB-EGF expression and the infiltration of cancer-immune cells using TIMER, as well as performed GSEA and ClueGo pathway analyses using TCGA databases. To validate the chemotactic role of HB-EGF, we conducted transwell migration assays using monocytes and macrophages, and performed transwell coculture experiments between Macrophage M2 and lung cancer cells. The levels of HB-EGF expression and the accumulation of M1/M2 macrophages in lung tissue were determined through immunohistochemical staining assays.
Results: High levels of HB-EGF gene expression were found to be significantly associated with poor overall survival in lung adenocarcinoma (LUAD) but not in lung squamous cell carcinoma (LUSC). In LUAD, HB-EGF expression showed positive correlations with the infiltration of monocytes, macrophages, neutrophils, and dendritic cells, whereas such correlations were not observed in LUSC. The upregulation of HB-EGF was detected in tumor cells as well as in monocytes, macrophages, and dendritic cells. Functional pathway analysis revealed that HB-EGF is linked to multiple aspects of cancer hallmarks. Notably, in vitro studies have demonstrated that HB-EGF induces the migration of monocytes and macrophages, and contributes to cancer cell growth and migration in coculture experiments. Furthermore, HB-EGF exhibited higher expression levels in tumors compared to adjacent tissues and was positively associated with the M2 phenotype of macrophages in LUAD.
Conclusions: Elevated HB-EGF expression in LUAD was strongly associated with unfavorable survival outcomes. The presence of HB-EGF secreted by LUAD cells might contribute to the recruitment of immune suppressive cells within the tumor microenvironment. Taken together, HB-EGF represents a potential therapeutic target for inhibiting the progression of lung cancer, particularly in LUAD cases. |
