진행성 암에서의 신흥 바이오마커: 예후적 함의와 치료 목표로서의 잠재성

Abstract

Background The exploration of biomarkers is essential for treatment and personalized medicine in advanced cancers. This study investigated the prognostic and therapeutic implications of three emerging biomarkers: NEK9–EG5 axis in colon cancer, HER3 in ALK-positive non-small cell lung cancer (NSCLC), and PD- L1 expression with the tumor microenvironment (TME) of ALK-positive NSCLC. Methods For the colon cancer study, immunohistochemistry (IHC) analysis was conducted on tissue samples from 138 pT3 colon cancer patients to evaluate NEK9, EG5, and acetyl-α-tubulin expression. In the NSCLC study, IHC staining was performed on ALK-positive NSCLC tissue specimens before/after ALK inhibitors to assess HER3 expression, with western blot analysis used to confirm HER3 activation via the HRG1 ligand. Additionally, combination therapy effects of ALK and EGFR inhibitors were tested on ALK-positive NSCLC cell lines. For the PD-L1 expression and TME study in ALK-positive NSCLC, IHC analysis of CD3, CD4, CD8, FOXP3, and PD-1 was conducted to examine T cell subsets, and the 22C3 and SP263 assays were used for PD-L1 expression. Further, spatial transcriptomic analysis was performed on two representative ALK-positive NSCLC cases (one PD-L1 positive and one PD-L1 negative) to compare immune cell-related gene expression patterns. Results The IHC analysis of pT3 colon cancer patients revealed that NEK9 expression was significantly associated with distant metastasis (P = 0.032) and served as an independent predictive factor for metastasis (HR = 3.365, P < 0.001). The NEK9-EG5 axis was active, and simultaneous high expression of both NEK9 and EG5 was associated with mitosis in colon cancer cell lines, indicating that the NEK9– EG5 axis could predict metastatic potential in pT3 colon cancer patients. In ALK-positive NSCLC patients (n = 96), high HER3 expression correlated with poorer survival, especially in EML4-ALK variant 1/2 (V1/V2) patients and this correlation was significant in specimens collected both before and after ALK inhibitor treatment (P = 0.022 and 0.004, respectively). Western blot analysis confirmed HER3 activation through HRG1-induced expression of pHER3, pAKT, and pERK. Combining ALK and EGFR inhibitors significantly reduced receptor tyrosine kinase signaling in ALK-positive NSCLC cell lines. For PD-L1 expression and TME in ALK-positive NSCLCs (n = 68), the IHC study did not yield significant or explainable results regarding the relationship between T cell subsets and PD-L1. However, spatial transcriptomic analysis demonstrated minimal coexpression rates of CD274 (encoding PD-L1) and PDCD1 (encoding PD-1) in PD-L1 positive cases with higher CD68 (pan-macrophages) and CD163 (M2-like macrophages) in these coexpression spots, compared to the PD-L1 negative case. This implies that ALK-positive NSCLC may not involve direct contact between PD-1 receptor and PD-L1 ligand cells, potentially explaining the limited efficacy of immune checkpoint inhibitors in these patients. Notably, CD163 expression correlated with significantly higher CD274 levels, while PDCD1 levels showed little difference between PD-L1 positive and negative cases. The findings suggest that higher levels of PD- L1 positive tumor-associated macrophages TAMs and relatively lower levels of PD-1 positive immune cells do not necessarily lead to immune escape of tumor cells. Conclusions These findings suggest that targeting the NEK9–EG5 axis, assessing HER3 expression, and understanding PD-L1 interactions in the tumor microenvironment may provide promising strategies for personalized treatment approaches in colon cancer and ALK-positive NSCLC. Keywords: HER3, NEK9, PD-L1, ALK, non-small cell lung cancer, colon cancer