背景:单核细胞增生李斯特菌是一种食源性病原体,会导致严重的疾病,尤其是免疫系统较弱或合并症的人。近年来,宿主与病原体之间以及病原体与肿瘤细胞之间的相互作用一直存在争议。然而,目前还不清楚细菌如何与肿瘤细胞相互作用,以及这种相互作用是否会影响肿瘤进展和治疗。
方法:在本研究中,我们评估了单核细胞增生李斯特菌在肿瘤前期和结直肠癌细胞增殖和致瘤潜能中的作用。
结果:我们的发现表明,热灭活的单核细胞增生李斯特菌与肿瘤前或结直肠癌细胞之间的相互作用导致增殖诱导;此外,通过使用三维细胞培养模型,获得的数据表明,单核细胞增生李斯特菌能够增加肿瘤前细胞和结直肠癌细胞的致瘤潜能.然后将观察到的效果证实为单核细胞增生李斯特菌特异性,使用无害李斯特菌作为阴性对照。最后,数据表明,胰岛素生长因子1受体(IGF1R)级联反应是人类结直肠腺癌细胞系中单核细胞增生李斯特菌诱导作用的可能机制之一。
结论:这些发现,虽然是初步的,提示肿瘤壁龛中致病菌细胞的存在可能直接诱导,增加,并刺激肿瘤进展。
BACKGROUND: Listeria monocytogenes is a foodborne pathogen, which can cause a severe illness, especially in people with a weakened immune system or comorbidities. The interactions between host and pathogens and between pathogens and tumor cells have been debated in recent years. However, it is still unclear how bacteria can interact with tumor cells, and if this interaction can affect tumor progression and therapy.
METHODS: In this study, we evaluated the involvement of L. monocytogenes in pre-neoplastic and colorectal cancer cell proliferation and tumorigenic potential.
RESULTS: Our findings showed that the interaction between heat-killed L. monocytogenes and pre-neoplastic or colorectal cancer cells led to a proliferative induction; furthermore, by using a three-dimensional cell culture model, the obtained data indicated that L. monocytogenes was able to increase the tumorigenic potential of both pre-neoplastic and colorectal cancer cells. The observed effects were then confirmed as L. monocytogenes-specific, using Listeria innocua as negative control. Lastly, data suggested the Insulin Growth Factor 1 Receptor (IGF1R) cascade as one of the possible mechanisms involved in the effects induced by L. monocytogenes in the human colorectal adenocarcinoma cell line.
CONCLUSIONS: These findings, although preliminary, suggest that the presence of pathogenic bacterial cells in the tumor niches may directly induce, increase, and stimulate tumor progression.