IL-6中和單株抗體抑制DNMT1高表現的HER2陽性乳癌侵襲

Neutralizing Monoclonal Antibody to IL-6 Inhibits Invasion of HER2- Positive Breast Cancer with High DNMT1 Expression

表觀遺傳學調控的改變，包括去氧核醣核酸甲基轉移酶1（DNMT1）導致的DNA高甲基化，與惡性表型的獲得有關。白細胞介素6（IL-6）是一種多功能細胞因子，被發現可透過調節DNMT1引起表觀遺傳學變化。然而，IL-6和DNMT1可能影響乳癌的進程仍不清楚。TIMER2.0網絡伺服器用於對癌症基因組圖譜（TCGA）中的DNMT1表現進行綜合分析。透過TISCH資料庫的單細胞定序資料探索腫瘤免疫微環境中DNMT1和IL-6之間的關聯，以用於腫瘤學以外的應用。在乳癌細胞系中檢查了IL-6和DNMT1的表達。比較高表達和低表達IL-6/DNMT的乳癌細胞系之間以及用/不用IL-6抗體處理的細胞之間的細胞侵襲活性。乳腺腫瘤組織中DNMT1 mRNA水準顯著上升（p < 0.001），其突變率小於0.02%（12/1026）。在乳癌中發現IL-6和DNMT1表現量呈正相關。單細胞定序數據顯示，DNMT1主要表達於惡性細胞以及巨噬細胞、CD4 T細胞和CD8 T細胞等先天性和適應性免疫細胞中，而IL-6僅在惡性細胞中表達。在乳癌細胞系中，與IL-6和DNMT1低表達的人類表皮生長因子受體2（HER2）陽性細胞系SKBR3相比，IL-6和DNMT1高表達的HER2陽性MDA-MB-453表現出更高的侵襲性。最後，IL-6重組蛋白（10 ng/ml）顯著促進低IL-6/低DNMT1 SKBR3的侵襲能力，而IL-6抗體（10μg/ml）處理顯著抑制高IL-6/低DNMT1 SKBR3的侵襲活性。IL-6-DNMT1軸可能是腫瘤免疫微環境中HER2陽性乳癌進展的原因。我們的研究表明，IL-6抑制與抗HER2治療相結合可能是治療惡性細胞的有效方法，特別是對於HER2陽性患者，有可能成為標準治療策略。

Altered epigenetic regulation, including DNA hypermethylation by DNA methyltransferase 1 (DNMT1), has been implicated in the acquisition of malignant phenotypes. Interleukin-6 (IL-6) is a multifunctional cytokine found to cause epigenetic changes by regulating DNMT1. However, the role of IL-6 and DNMT1 in breast cancer progression is still unclear. The TIMER2.0 web server was used for a comprehensive analysis of DNMT1 expression from The Cancer Genome Atlas (TCGA). The association between DNMT1 and IL-6 in the tumor immune microenvironment was explored via single-cell sequencing data from the TISCH database for applications outside oncology. IL-6 and DNMT1 expression levels were examined in breast cancer cell lines. Cell invasion activity was compared between breast cancer cell lines with high and low IL-6/DNMT1 expression, as well as between cells treated with and without IL-6 antibody. DNMT1 mRNA levels were significantly higher in breast tumor tissues (p < 0.001), with a mutation rate of less than 0.02% (12/1026). A positive correlation was found between IL-6 and DNMT1 expression levels in breast cancer. Single-cell sequencing data showed that DNMT1 was primarily expressed in malignant cells and innate and adaptive immune cells, including macrophages, CD4 T cells, and CD8 T cells, whereas IL-6 expression was only observed in malignant cells. In breast cancer cell lines, the HER2-positive MDA-MB-453 cell line, which had high IL-6 and DNMT1 expression, exhibited greater invasiveness than the HER2-positive SKBR3 cell line, which had low IL-6 and DNMT1 expression. Furthermore, IL-6 recombinant protein (10 ng/ ml) significantly promoted the invasion ability of low IL-6/low DNMT1 SKBR3 cells, whereas IL-6 antibody (10μg/ml) treatment significantly suppressed the invasion activity of high IL-6/high DNMT1 MDA-MB-453 cells. The IL-6-DNMT1 axis may be responsible for HER2-positive breast cancer progression in the tumor immune microenvironment. This study suggests that combining IL-6 inhibition with anti-HER2 therapy may be a promising approach for treating malignant cells, particularly in HER2-positive patients, and could potentially become a standard therapeutic strategy.