You Kyu Sic, Kim Tae-Sung, Back Su Min, Park Jeong-Soo, Liu Kangdong, Seong Yeon-Sun, Kim Dong Joon, Yi Yong Weon
Department of Biochemistry, College of Medicine, Dankook University, Cheonan-si 31116, Republic of Korea.
Multidrug-Resistant Refractory Cancer Convergence Research Center (MRCRC), Dankook University, Cheonan-si 31116, Republic of Korea.
Int J Mol Sci. 2025 Jun 26;26(13):6139. doi: 10.3390/ijms26136139.
Janus kinase 2 (JAK2) inhibitors have gained regulatory approval for treating various human diseases. While the JAK2/signal tranducer and activator of transcription 3 (STAT3) pathway plays a role in tumorigenesis, JAK2/STAT3 inhibitors have shown limited therapeutic efficacy in triple-negative breast cancer (TNBC). In this study, we assessed the antiproliferative effects of clinically approved JAK2 inhibitors in TNBC cell lines (MDA-MB-231 and HS578T) using the MTT assay. Among the four JAK2 inhibitors evaluated (fedratinib, cerdulatinib, peficitinib, and filgotinib), fedratinib significantly inhibited the proliferation of TNBC cells with IC values below 2 μM. Fedratinib also demonstrated superior efficacy in inhibiting long-term colony formation compared to other JAK2 inhibitors. Western blot analyses showed that fedratinib uniquely inhibits the phosphoinositide 3-kinase (PI3K)/AKT pathway and moderately affects the MAP kinase/ERK kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway, in addition to targeting JAK2/STAT3 signaling. Moreover, fedratinib distinctly decreased MYC and cyclin D1 protein levels while inducing poly (ADP-ribose) polymerase (PARP) cleavage and apoptotic cell death more effectively than other JAK2 inhibitors. We next investigated the effects of simultaneously inhibiting JAK2/STAT3 together with the MEK/ERK or PI3K/AKT pathways, as well as the impact of triple pathway inhibition. Notably, combining ceduratinib with either cobimetinib (MEK inhibitor) and ipatasertib (AKT inhibitor) or trametinib (MEK inhibitor) and alpelisib (PI3K inhibitor) mimicked the effects of fedratinib on the cell proliferation, MYC and cyclin D1 suppression, and pro-apoptotic protein induction. These finding suggest that JAK2 inhibition enhances the anticancer effects of concurrent MEK/ERK and PI3K/AKT pathway inhibition, while JAK2 inhibition alone shows minimal efficacy in TNBC cells.
Janus激酶2（JAK2）抑制剂已获得治疗多种人类疾病的监管批准。虽然JAK2/信号转导子和转录激活因子3（STAT3）通路在肿瘤发生中起作用，但JAK2/STAT3抑制剂在三阴性乳腺癌（TNBC）中的治疗效果有限。在本研究中，我们使用MTT法评估了临床批准的JAK2抑制剂对TNBC细胞系（MDA-MB-231和HS578T）的抗增殖作用。在所评估的四种JAK2抑制剂（非格司亭、西杜替尼、培非替尼和非戈替尼）中，非格司亭显著抑制TNBC细胞的增殖，IC值低于2μM。与其他JAK2抑制剂相比，非格司亭在抑制长期集落形成方面也表现出卓越的疗效。蛋白质免疫印迹分析表明，除了靶向JAK2/STAT3信号传导外，非格司亭独特地抑制磷酸肌醇3激酶（PI3K）/AKT通路，并适度影响丝裂原活化蛋白激酶/细胞外信号调节激酶（MEK）/细胞外信号调节激酶（ERK）通路。此外，非格司亭明显降低MYC和细胞周期蛋白D1的蛋白水平，同时比其他JAK2抑制剂更有效地诱导聚（ADP-核糖）聚合酶（PARP）裂解和凋亡性细胞死亡。接下来，我们研究了同时抑制JAK2/STAT3与MEK/ERK或PI3K/AKT通路的效果，以及三通路抑制的影响。值得注意的是，将西杜替尼与考比替尼（MEK抑制剂）和伊帕替尼（AKT抑制剂）或曲美替尼（MEK抑制剂）和阿培利司（PI3K抑制剂）联合使用，模拟了非格司亭对细胞增殖、MYC和细胞周期蛋白D1抑制以及促凋亡蛋白诱导的作用。这些发现表明，JAK2抑制增强了同时抑制MEK/ERK和PI3K/AKT通路的抗癌效果，而单独的JAK2抑制在TNBC细胞中显示出最小的疗效。
