PO.PR02.01 · 预防研究
苯乙醛通过内质网应激诱导凋亡并增强5-FU对结直肠癌的治疗效果
Phenylacetaldehyde induces apoptosis through endoplasmic reticulum stress and potentiates the effect of 5-FU treatment in colorectal cancer
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摘要 Abstract
中文摘要
引言：苯乙醛（PAA）是苯丙氨酸代谢的产物，由微生物群产生，并已在乳腺癌中显示出抗癌特性。由于肠道稳态受肠道微生物组的影响，我们研究了PAA对结直肠癌（CRC）的作用。
方法：采用靶向GC-MS/MS和宏基因组测序，对30例CRC患者和30例健康对照患者组成的测试队列的血清PAA水平和粪便微生物群进行分析。对75例CRC患者和53例健康对照患者组成的验证队列的血清PAA水平进行分析。培养CRC细胞系和CRC患者来源的类器官，单独使用PAA或与5-氟尿嘧啶（5-FU）联合处理，随后在体外评估活力、增殖和细胞死亡。同时在体内检测单独使用PAA或与5-FU联合对肿瘤生长的影响。我们利用RNA测序、蛋白质印迹、免疫染色、ROS定量测定、半胱氨酸和谷胱甘肽定量，鉴定了PAA处理所诱导的机制。
结果：在我们的研究人群和验证队列中，与健康对照相比，CRC患者循环中的PAA水平显著降低。宏基因组测序表明，与PAA水平正相关的细菌在健康对照中的丰度显著更高；而与PAA负相关的细菌在CRC中的丰度更高。在体外，PAA以浓度依赖的方式抑制了CRC细胞系以及人源类器官的活力和集落形成。在机制上，PAA处理诱导ROS生成，导致半胱氨酸和还原型谷胱甘肽耗竭。RNA测序和免疫印迹研究表明，PAA通过诱导内质网应激相关的自噬来抑制CRC，并伴随PI3K/AKT/mTOR和ERK通路的下调。当与5-FU联合使用时，PAA增强了5-FU在活力、细胞死亡、DNA损伤和肿瘤生长方面的效力。
结论：细菌代谢物PAA通过内质网应激诱导的自噬以及PI3K/AKT/mTOR和ERK通路的下调，增加了CRC细胞死亡。PAA还通过诱导DNA损伤增强了5-FU的化疗疗效。这些发现值得进一步探索PAA作为潜在CRC生物标志物和新型治疗药物的价值。
查看英文原文 English abstract
Introduction: Phenylacetaldehyde (PAA), a product of phenylalanine metabolism, is generated by microbiota and has demonstrated anticancer properties in breast cancer. As intestinal homeostasis is influenced by the gut microbiome, we investigated the effect of PAA on colorectal cancer (CRC).
Methods: Serum PAA levels and feces microbiota from a test cohort of 30 CRC patients and 30 healthy control patients were analyzed by targeted GC-MS/MS and metagenomic sequencing. A validation cohort of 75 CRC patients and 53 healthy control patients was analyzed for PAA levels in serum. CRC cell lines and CRC-patient-derived organoids were cultured and treated with PAA alone or in combination with 5-fluorouracil (5-FU), then evaluated for viability, proliferation, , and cell death in vitro . The effect of PAA alone or in combination with 5-FU on tumor growth was also tested in vivo . We identified the mechanisms induced by PAA treatment using RNA sequencing, western blot, immunostaining, ROS quantification assay, cysteine and glutathione quantification.
Results: PAA levels were significantly decreased in the circulation of CRC patients compared to healthy controls in our study population and the validation cohort. Metagenomic sequencing indicated the bacteria that positively correlated with PAA levels were significantly more abundant in healthy controls; while bacteria that negatively correlated with PAA were more abundant in CRC. In vitro , PAA inhibited the viability and colony formation of CRC cell lines as well as human-derived organoids in a concentration-dependent manner. Mechanistically, PAA treatment induced generation of ROS leading to cysteine and reduced glutathione depletion. An investigation by RNA sequencing and immunoblotting showed that PAA inhibits CRC by inducing endoplasmic reticulum stress-induced autophagy accompanied by downregulation in PI3K/AKT/mTOR and ERK pathways. When combined with 5-FU, PAA enhanced the potency of 5-FU on viability, cell death, DNA damage and tumor growth.
Conclusions: The bacteria metabolite PAA increased CRC cell death by endoplasmic reticulum stress-induced autophagy and downregulation of the PI3K/AKT/mTOR and ERK pathways. PAA also potentiated the chemotherapeutic efficacy of 5-FU through induction of DNA damages. These findings warrant further exploration of PAA as a potential CRC biomarker and novel therapeutic agent.
利益披露 Disclosure
S. Ferrandon, None..
J. Fedro, None..
R. Aoun, None..
Z. Wang, None..
C. Chitchumroonchokchai, None..
H. Qin, None..
S. Clinton, None..
M. F. Kalady, None.