PO.TB04.02 · 肿瘤生物学
短端粒在人源化端粒（HuT）小鼠中限制Braf V600E驱动的黑色素瘤发生
Short telomeres limit braf V600E driven melanomagenesis in humanized telomere (HuT) mice
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
端粒长度影响基因组稳定性、免疫功能和癌症易感性。尽管小鼠被广泛用于模拟肿瘤发生，但其端粒比人类长得多，且通常不施加端粒依赖性的增殖限制。为确定类人端粒如何影响黑色素瘤的发展，我们使用了具有短的、人类范围端粒（7-9 kb）的人源化端粒（HuT）小鼠（Tert h/h和Tert h/-），并将其与野生型C57BL/6（Tert +/+）小鼠（约50 kb）进行比较。在2月龄时通过他莫昔芬激活Braf +/LSL-V600E；Tyr::CreERT +/o转基因小鼠中的致癌性Braf V600E，随后每周进行UV照射以模拟慢性阳光驱动的黑色素瘤。对肿瘤起始、生长和负荷进行40-60周的监测。组织学、免疫组织化学、qRT-PCR，组织和肿瘤通过H&E、IHC、qRT-PCR、gammaH2AX、TRF2和端粒分析进行检测，以评估肿瘤生物学和基因组完整性。通过流式细胞术分析外周血、骨髓、脾脏和肿瘤中的免疫细胞群。建立原代黑色素瘤细胞培养物，并对其Tert mRNA表达、端粒酶活性和体细胞突变分析进行评估。Kaplan-Meier分析显示，与野生型对照相比，HuT小鼠的黑色素瘤发病显著延迟（Tert h/h，p = 0.0053；Tert h/-，p = 0.0001；Log-rank检验）。Tert h/-小鼠每只动物发生的肿瘤数量少于Tert h/h和野生型小鼠。有趣的是，雄性Tert h/h小鼠（而非野生型或Tert h/-小鼠）表现出比雌性同窝小鼠更快的黑色素瘤发展（p = 0.0005），这与在男性中观察到的较高黑色素瘤发病率相一致。组织学分析确认了痣和色素细胞。这些发现表明，短的人源化端粒以基因型、年龄和性别依赖的方式抑制Braf V600E驱动的黑色素瘤发生。HuT小鼠模型提供了一个生理相关的平台，用于研究端粒调控的黑色素瘤生物学、免疫-肿瘤相互作用和基因组不稳定性，为临床前癌症研究提供了有价值的见解。
查看英文原文 English abstract
Telomere length influences genomic stability, immune function, and cancer susceptibility. Although mice are widely used to model tumorigenesis, their telomeres are much longer than humans and generally do not impose telomere-dependent proliferative limits. To determine how human-like telomeres affects melanoma development, we used humanized telomere (HuT) mice ( Tert h/h and Tert h/- ) with short, human-range telomeres (7-9 kb) and compared them to wildtype C57BL/6 ( Tert +/+ ) mice (~50 kb). Oncogenic Braf V600E was activated in Braf +/LSL-V600E ; Tyr::CreERT +/o transgenic mice at 2 months of age via tamoxifen, followed by weekly UV exposure to model chronic sunlight-driven melanoma. Tumor initiation, growth, and burden were monitored for 40-60 weeks. Histology, immunohistochemistry, qRT-PCR, Tissues and tumors were analyzed by H&E, IHC, qRT-PCR, gammaH2AX, TRF2, and telomere analysis assessed tumor biology and genomic integrity. Immune cell populations in peripheral blood, bone marrow, spleen, and tumors were analyzed by flow cytometry. Primary melanoma cell cultures were established and evaluated for Tert mRNA expression, telomerase activity, and somatic mutation analysis. Kaplan-Meier analysis showed significantly delayed melanoma onset in HuT mice compared to wild-type controls ( Tert h/h , p = 0.0053; Tert h/- , p = 0.0001; Log-rank test). Tert h/- mice developed fewer tumors per animal than both Tert h/h and wildtype mice. Interestingly, male Tert h/h mice, but not wildtype or Tert h/- mice, exhibited more rapid melanoma development than female littermates ( p = 0.0005), mirroring the higher melanoma incidence observed in men. Histological analysis confirmed nevi and pigmented cells. These findings demonstrate that short, humanized telomeres suppress Braf V600E -driven melanomagenesis in a genotype-, age-, and sex-dependent manner. The HuT mouse model provides a physiologically relevant platform to investigate telomere-regulated melanoma biology, immune-tumor interactions, and genomic instability, offering valuable insights for preclinical cancer research.
利益披露 Disclosure
M. Bin Kabir, None..
J. Liu, None..
F. Zhang, None..
K. Porter, None..
J. Zhu, None.