GPNA hydrochloride, as a substrate of γ-glutamyl transferase (GGT), can inhibit the activity of the glutamine (Gln) transporter ASCT2, with an IC50 of 250μM[1]. In addition, GPNA hydrochloride also inhibits the activity of the Na+-dependent carrier SNAT family proteins[2] and leucine and other neutral amino acid transport carriers[3]. Moreover, GPNA hydrochloride has the effect of inhibiting cancer development and metastasis[4]
In vitro, treatment of Ishikawa, HEC1A, and KLE cell lines with GPNA hydrochloride (1mM) significantly inhibits cell growth. Also, GPNA hydrochloride significantly inhibits the growth of 3D spheroids in Ishikawa and HEC1A cells[5]. When A549 cells are treated with GPNA hydrochloride (250μM), the compound exerts cytotoxic effects through GGT-mediated hydrolysis, resulting in reduced cell viability[6].
In vivo, GPNA hydrochloride (50mg/kg) is intraperitoneally injected into mice to deplete endogenous glutamine levels, followed by airway challenge with ovalbumin (OVA) to induce an asthma response. Mice treated with GPNA hydrochloride show significantly enhanced airway inflammation, with significantly elevated levels of pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6. Moreover, GPNA hydrochloride-treated mice also exhibit increased airway hyperresponsiveness, exacerbated lung tissue inflammation, and increased mucus production. GPNA hydrochloride significantly exacerbates asthma symptoms in mice, particularly neutrophil-mediated inflammatory responses[7]. GPNA hydrochloride (50mg/kg) in combination with Cetuximab (1mg/mouse) is intraperitoneally injected twice a week for 3 weeks to treat BALB/c nude mice bearing gastric cancer cells. GPNA hydrochloride significantly inhibits the proliferation of gastric cancer cells and enhances the inhibitory effect of Cetuximab on gastric cancer[8].
References:
[1] Lyda BR, Leary GP, Farnsworth J, et al. Discovery and Synthesis of Hydroxy-l-Proline Blockers of the Neutral Amino Acid Transporters SLC1A4 (ASCT1) and SLC1A5 (ASCT2). Molecules. 2024 May 15;29(10):2330.
[2] Freidman NJ, Briot C, Ryan RM. Characterizing unexpected interactions of a glutamine transporter inhibitor with members of the SLC1A transporter family. J Biol Chem. 2022 Aug;298(8):102178.
[3] Chiu M, Sabino C, Taurino G, et al. GPNA inhibits the sodium-independent transport system L for neutral amino acids. Amino Acids. 2017 Aug;49(8):1365-1372.
[4] Kong Y, Wu M, Wan X, et al. Lipophagy-mediated cholesterol synthesis inhibition is required for the survival of hepatocellular carcinoma under glutamine deprivation. Redox Biol. 2023 Jul;63:102732.
[5] Marshall AD, van Geldermalsen M, Otte NJ, et al. ASCT2 regulates glutamine uptake and cell growth in endometrial carcinoma. Oncogenesis. 2017 Jul 31;6(7):e367.
[6] Corti A, Dominici S, Piaggi S, et al. γ-Glutamyltransferase enzyme activity of cancer cells modulates L-γ-glutamyl-p-nitroanilide (GPNA) cytotoxicity. Sci Rep. 2019 Jan 29;9(1):891.
[7] Kim JM, Im YN, Chung YJ, et al. Glutamine deficiency shifts the asthmatic state toward neutrophilic airway inflammation. Allergy. 2022 Apr;77(4):1180-1191.
[8] Ma H, Wu J, Zhou M, et al. Inhibition of Glutamine Uptake Improves the Efficacy of Cetuximab on Gastric Cancer. Integr Cancer Ther. 2021 Jan-Dec;20:15347354211045349.
GPNA hydrochloride作为γ-谷氨酰转移酶(GGT)的底物，可抑制谷氨酰胺(Gln)转运蛋白ASCT2的活性，IC50为250μM[1]。此外，GPNA hydrochloride还对Na+依赖性载体SNAT家族蛋白[2]和亮氨酸及其它中性氨基酸转运载体的活性有抑制作用[3]。此外，GPNA hydrochloride还具有抑制癌症发育和转移的作用[4]。
在体外，GPNA hydrochloride（1mM）处理Ishikawa、HEC1A和KLE细胞系，能显著抑制细胞生长。同时，GPNA hydrochloride能显著抑制Ishikawa和HEC1A细胞的3D球体的生长 [5]。GPNA hydrochloride（250μM）处理A549细胞，GPNA hydrochloride通过γ-谷氨酰转肽酶（GGT）介导的水解作用产生细胞毒性效应，导致细胞活力降低[6]。
在体内，GPNA hydrochloride（50mg/kg）腹腔注射至小鼠中用于耗竭内源性谷氨酰胺水平，随后对小鼠进行卵清蛋白（OVA）气道挑战以诱导哮喘反应。GPNA hydrochloride处理的小鼠在气道炎症方面表现出显著增强的反应，促炎细胞因子（如TNF-α、IL-1β和IL-6）水平显著升高。此外，GPNA hydrochloride处理的小鼠还表现出气道高反应性增强、肺组织炎症加重以及黏液分泌增加。GPNA hydrochloride显著加剧了小鼠的哮喘症状，尤其是中性粒细介导的炎症反应[7]。GPNA hydrochloride（50mg/kg）联合Cetuximab（1mg/只）腹腔注射，每周2次，持续3周，用于处理抑制胃癌细胞的BALB/c裸鼠。GPNA hydrochloride显著抑制了胃癌细胞的增殖，并增强了Cetuximab对胃癌的抑制效果[8]。