Background: The combination of epirubicin, cisplatin, and 5-fluorouracil (ECF) is widely used for gastric cancer treatment. However, cancer cells can acquire chemoresistance over multiple treatment cycles, leading to recurrence. This study aimed to investigate a novel biomarker for predicting ECF resistance and its biological roles in gastric cancer.

Methods: ECF-resistant (ECF-R) gastric cancer cell lines were established through stepwise ECF treatment. Transcriptome analysis was performed to identify resistance-related genes, which were validated in tumor organoids and in vivo models. Additionally, gastric cancer patient tumor tissues were analyzed for clinical relevance.

Results: Transcriptome analysis revealed that NINJURIN2 and CD44 were highly expressed in ECF-R cells but rarely expressed in normal gastric tissues. NINJURIN2 inhibition significantly increased chemosensitivity to ECF in vitro and in vivo. Liquid chromatography-tandem mass spectrometry identified periostin as a binding partner of NINJURIN2, mediating chemoresistance. Furthermore, VAV2 phosphorylation was markedly upregulated in ECF-R cells but was inhibited by NINJURIN2 knockdown. Clinical analysis showed that high NINJURIN2 expression correlated with poor survival outcomes in gastric cancer patients.

Conclusion: Our findings suggest that NINJURIN2 can be used as a novel biomarker for chemoresistant gastric cancer patients and that inhibiting NINJURIN2 along with standard chemotherapy could prevent chemoresistance-associated relapse in gastric cancer.

Keywords: Cancer initiating cells; Chemoresistance; Gastric cancer cells; Ninjurin2; Organoid.

© 2025. The Author(s).

背景:

表阿霉素、顺铂和氟尿嘧啶（ECF）组合广泛用于胃癌治疗。然而，经过多次治疗后，癌细胞可以获得化疗耐药性，导致复发。本研究旨在调查一种预测 ECF 耐药性的新型生物标志物及其在胃癌中的生物学作用。

方法:

通过逐步施用 ECF 建立了对 ECF 耐药的胃癌细胞系。进行转录组分析以识别与耐药性相关的基因，并在肿瘤类器官和体内模型中进行了验证。此外，还分析了胃癌患者肿瘤组织的临床相关性。

结果:

转录组分析显示，NINJURIN2 和 CD44 在 ECF 耐药细胞中高度表达，但在正常胃组织中的表达很少。抑制 NINJURIN2 可显著增加对 ECF 的化疗敏感性（体外和体内）。液相色谱-串联质谱法确定 periostin 为 NINJURIN2 的结合伙伴，介导了化疗耐药性。此外，在 ECF 耐药细胞中 VAV2 磷酸化显著上调，但被 NINJURIN2 敲低所抑制。临床分析显示高 NINJURIN2 表达与胃癌患者的不良预后相关。

结论:

我们的研究结果表明，NINJURIN2 可作为预测化疗耐药性胃癌患者的新型生物标志物，并且抑制 NINJURIN2 结合标准化疗可以预防胃癌的化疗耐药相关复发。