Wu Yulin, Zhang Juan, Tian Yuanyang, Chi Shing Cho William, Xu Hong-Xi, Lin Zhi-Xiu, Xian Yan-Fang
School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
Department of Clinical Oncology, Queen Elizabeth Hospital, Kowloon, Hong Kong, China; Department of Pathology, Queen Elizabeth Hospital, Kowloon, Hong Kong, China.
J Adv Res. 2024 Sep 11. doi: 10.1016/j.jare.2024.09.006.
Gemcitabine (GEM) is the first-line drug for pancreatic ductal adenocarcinoma (PDAC), but drug resistance severely restricts its chemotherapeutic efficacy. Laminin subunit γ2 (LAMC2) plays a crucial role in extracellular matrix formation in the development of GEM-resistance. However, the biological function of LAMC2 in GEM resistance and its molecular mechanisms are still unclear. 20(S)-Ginsenoside Rh2 (Rh2), one of the principal active components isolated from Ginseng Radix et Rhizoma, possesses strong anti-tumor effects. However, the effects of Rh2 on overcoming GEM resistance and its action mechanisms remain to be elucidated.
This study aimed to determine the efficacy of Rh2 on overcoming GEM resistance and to explore its underlying molecular mechanisms.
Clinical study, Western blotting, publicly available databasesand bioinformatic analyses were performed to investigate the protein expression of LAMC2 in the GEM-resistant PDAC patients and the acquired GEM-resistant PDAC cells. Then, the effects of Rh2 on overcoming the GEM resistance in PDAC were evaluated both in vitro and in vivo. Stable silencing or overexpression of LAMC2 in the GEM-resistant PDAC cells were established for validating the role of LAMC2 on Rh2 overcoming the GEM resistance in PDAC.
The protein expression of LAMC2 was markedly increased in the GEM-resistant PDAC patient biopsies compared to the sensitive cases. The protein expression of LAMC2 was significantly higher in the acquired GEM-resistant PDAC cells than that in their parental cells. Rh2 enhanced the chemosensitivity of GEM in the GEM-resistant PDAC cells, and inhibited the tumor growth of Miapaca-2-GR cell-bearing mice and KrasTrp53Tg (Pdx1-cre/Esr1*) #Dam/J (KPC) mice. Rh2 effectively reversed the GEM resistance in Miapaca-2-GR and Capan-2-GR cells by inhibiting LAMC2 expression through regulating the ubiquitin-proteasome pathway. Knockdown of LAMC2 enhanced the chemosensitivity of GEM and the effects of Rh2 on overcoming the GEM resistance in PDAC cells and the orthotopic PDAC mouse model. Conversely, LAMC2 overexpression aggravated the chemoresistance of GEM and abolished the effects of Rh2 on overcoming GEM resistance via modulating ATP-binding cassette (ABC) transporters leading to the active GEM efflux.
LAMC2 plays an important role in the GEM resistance in PDAC, and Rh2 is a potential adjuvant for overcoming the chemoresistance of GEM in PDAC.
吉西他滨（GEM）是胰腺导管腺癌（PDAC）的一线治疗药物，但耐药性严重限制了其化疗效果。层粘连蛋白亚基γ2（LAMC2）在GEM耐药性发展过程中的细胞外基质形成中起关键作用。然而，LAMC2在GEM耐药中的生物学功能及其分子机制仍不清楚。20（S）-人参皂苷Rh2（Rh2）是从人参中分离出的主要活性成分之一，具有很强的抗肿瘤作用。然而，Rh2对克服GEM耐药性的作用及其作用机制仍有待阐明。
本研究旨在确定Rh2克服GEM耐药性的疗效，并探讨其潜在的分子机制。
进行临床研究、蛋白质印迹法、公开可用数据库和生物信息学分析，以研究LAMC2在GEM耐药性PDAC患者和获得性GEM耐药性PDAC细胞中的蛋白表达。然后，在体外和体内评估Rh2对克服PDAC中GEM耐药性的作用。在GEM耐药性PDAC细胞中建立LAMC2的稳定沉默或过表达，以验证LAMC2在Rh2克服PDAC中GEM耐药性的作用。
与敏感病例相比，GEM耐药性PDAC患者活检组织中LAMC2的蛋白表达明显增加。获得性GEM耐药性PDAC细胞中LAMC2的蛋白表达明显高于其亲本细胞。Rh2增强了GEM耐药性PDAC细胞对GEM的化学敏感性，并抑制了携带Miapaca-2-GR细胞的小鼠和KrasTrp53Tg（Pdx1-cre/Esr1*）#Dam/J（KPC）小鼠的肿瘤生长。Rh2通过调节泛素-蛋白酶体途径抑制LAMC2表达，有效逆转了Miapaca-2-GR和Capan-2-GR细胞中的GEM耐药性。敲低LAMC2增强了GEM的化学敏感性以及Rh2对克服PDAC细胞和原位PDAC小鼠模型中GEM耐药性的作用。相反，LAMC2过表达加剧了GEM的化学耐药性，并通过调节ATP结合盒（ABC）转运蛋白导致活性GEM外排，消除了Rh2克服GEM耐药性的作用。
LAMC2在PDAC的GEM耐药中起重要作用，Rh2是克服PDAC中GEM化学耐药性的潜在佐剂。
