PO.CL01.01 · 临床研究
MYCL拷贝数扩增提示小细胞肺癌中血管生成的激活
The copy number amplification of MYCL indicated activation of angiogenesis in small cell lung cancer
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景：MYC家族基因（MYC/MYCN/MYCL）扩增是小细胞肺癌（SCLC）中的常见现象，已被广泛报道可促进肿瘤血管生成。然而，以往研究主要聚焦于MYC和MYCN，而MYCL扩增的作用由于频率相对较低而在很大程度上尚未被探索。在此，我们旨在表征MYCL扩增在SCLC中的分布，并阐明其与血管生成相关的潜在机制。
方法：共招募了135例来自北京大学人民医院、分期为IA至IIIB的手术切除SCLC患者。使用三色MYC旁系同源基因FISH探针评估MYC家族基因的扩增模式。扩增状态定义为样本中每个细胞平均每个MYC旁系同源基因≥4个信号。在组织微阵列（TMA，n=96）上进行免疫组化（IHC，CD31/PAS）和多重免疫组化（mIHC，CD31/CD3/CD68/CD11b/PanCK/Ki67），以量化微血管密度（MVD）和内皮细胞比例。对SCLC患者（n=20）进行配对全基因组测序（WGS）和单细胞RNA测序（scRNA-seq），以确定MYCL扩增状态和细胞比例用于功能分析。
结果：在135例SCLC样本中，共有9例被鉴定为MYCL扩增样本（6.7%）。与非扩增样本（n=89）相比，MYCL扩增样本（n=7）中观察到更高比例的内皮细胞（Mann-Whitney U检验，p=9.5×10⁻³），MYCL扩增SCLC中的MVD也更高（p=5.7×10⁻³）。为进一步探索潜在机制，我们基于WGS结果对MYCL扩增（n=6）和非扩增（n=14）SCLC样本进行了scRNA-seq。共199,644个细胞被聚类并注释为28种细胞亚型，在MYCL扩增样本中进一步证实了血管内皮细胞比例升高。此外，MYCL扩增样本表现出细胞黏附、内皮细胞迁移和血管生成通路的激活，提示与MYCL扩增相关的血管形态发生过程高度活化。同时，我们还使用AddModuleScore发现MYCL扩增样本中缺氧标签评分更高，并通过CellChat发现从MYCL+肿瘤细胞到内皮细胞的VEGF信号介导的通讯增强，提示MYCL+肿瘤细胞可能在缺氧肿瘤微环境中通过激活的VEGF通路驱动血管生成。
结论：MYCL扩增表现出更高的内皮比例和升高的血管密度，可能通过缺氧肿瘤与VEGF诱导的血管生成之间激活的相互作用实现，这可能作为SCLC抗血管生成治疗的潜在生物标志物。
查看英文原文 English abstract
Background: Amplification of MYC family genes (MYC/MYCN/MYCL), a common phenomenon in small cell lung cancer (SCLC), has been widely reported to promote tumor angiogenesis. However, previous studies mainly focused on MYC and MYCN, while the role of MYCL amplification remains largely unexplored due to relatively low frequency. Here we aim to characterize the distribution of MYCL amplification in SCLC and elucidate the potential mechanism related to angiogenesis.
Methods: A total of 135 surgically resected SCLC patients with stage IA to IIIB were recruited from Peking University People's Hospital. A triple-color MYC-paralogs FISH probe was used to assess amplification patterns of MYC family genes. The amplification status were defined in the samples with ≥ 4 signals of each MYC-paralogs per cell in average. Immunohistochemistry (IHC, CD31/PAS) and multiplex IHC (mIHC, CD31/CD3/CD68/CD11b/PanCK/Ki67) were performed on tissue microarrays (TMA, n = 96) to quantify microvessel density (MVD) and endothelial cell proportion. Paired whole genome sequencing (WGS) and single-cell RNA sequencing (scRNA-seq) of SCLC patients (n = 20) were performed to define MYCL amplification status and cell proportion for functional analysis.
Results: Among the 135 SCLC samples, a total of 9 samples were identified as MYCL-amplified samples (6.7%). A higher proportion of endothelial cells in MYCL-amplified samples (n = 7) were observed compared to non-amplified samples (n = 89, Mann-Whitney U test, p = 9.5×10 -3 ), as well as higher MVD in MYCL-amplified SCLC (p = 5.7×10 -3 ). To further explore potential mechanism, we performed scRNA-seq in MYCL-amplified (n = 6) and non-amplified (n = 14) SCLC samples based on WGS results. A total of 199,644 cells were clustered and annotated into 28 cell subtypes, and elevated vascular endothelial cell proportion were further confirmed in MYCL-amplified samples. Additionally, MYCL-amplified samples exhibited the activation of cell adhesion, endothelial cell migration and angiogenesis pathways, indicating the highly activated vasculature morphogenesis process associated with MYCL amplification. Meanwhile, we also found higher hypoxia signature scores in MYCL-amplified samples using AddModuleScore, as well as enhanced VEGF signaling-mediated communication from MYCL+ tumor cells to endothelial cells by CellChat, indicating that MYCL+ tumor cells may drive angiogenesis through the activated VEGF pathway in hypoxic tumor microenvironment.
Conclusions: The amplification of MYCL exhibited higher endothelial proportion and elevated vascular density, potentially through activated interaction between hypoxic tumor and VEGF-induced angiogenesis, which may serve as potential biomarkers for anti-angiogenic therapy in SCLC.
利益披露 Disclosure
Z. Yuan, None..
J. Zhang, None..
Y. Ju, None..
X. Wu, None..
M. Qiu, None..
X. Li, None.