TM4SF4,也称为Transmembrane 4 Superfamily Member 4,是一种跨膜蛋白,属于四跨膜蛋白超家族(Tetraspanins)。这个家族的成员在细胞信号传导、细胞增殖、细胞粘附和迁移中发挥着重要作用。TM4SF4在多种组织中表达,包括肠道、肝脏和胰腺,并在细胞增殖和再生过程中发挥作用。
在肠道中,TM4SF4与人类硫胺素转运蛋白-2(hTHTR-2)相互作用,影响硫胺素的吸收。研究显示,TM4SF4的过表达可以显著提高硫胺素的吸收,而TM4SF4的沉默则会降低硫胺素的吸收[4]。
在肝脏中,TM4SF4的表达在肝再生过程中增强。研究发现,在肝部分切除术后,大鼠肝脏中的TM4SF4表达增加,表明TM4SF4可能参与细胞增殖和肝再生[2]。此外,TM4SF4在急性肝损伤中也被过度表达,并通过TNF-alpha和HGF/c-met信号通路加速肝损伤[3]。
在胰腺中,TM4SF4的表达在α细胞和β细胞中较高,并且可以用于高纯度地分离活细胞[1]。这表明TM4SF4可能参与胰岛细胞的分化和功能。
TM4SF4在癌症中也发挥着重要作用。研究发现,TM4SF4在肝细胞癌(HCC)中过度表达,并且可以促进肿瘤细胞的生长和转移[7,8]。此外,TM4SF4在肺和乳腺癌中也是潜在的生物标志物和治疗方法[6]。
此外,TM4SF4还与长链非编码RNA(lncRNA)ST8SIA6-AS1和miR-651-5p相互作用,影响肝细胞癌的进展。ST8SIA6-AS1通过海绵作用抑制miR-651-5p,而miR-651-5p通过靶向TM4SF4抑制肝细胞癌的增殖和迁移[5]。
综上所述,TM4SF4是一种重要的跨膜蛋白,参与细胞增殖、再生和癌症发生。它在多种组织中表达,并在多种生物学过程中发挥作用。TM4SF4的研究有助于深入理解细胞信号传导和疾病发生机制,为疾病的治疗和预防提供新的思路和策略。
参考文献:
1. Muraro, Mauro J, Dharmadhikari, Gitanjali, Grün, Dominic, de Koning, Eelco J P, van Oudenaarden, Alexander. 2016. A Single-Cell Transcriptome Atlas of the Human Pancreas. In Cell systems, 3, 385-394.e3. doi:10.1016/j.cels.2016.09.002. https://pubmed.ncbi.nlm.nih.gov/27693023/
2. Liu, Z, Zhao, M, Yokoyama, K K, Li, T. . Molecular cloning of a cDNA for rat TM4SF4, a homolog of human il-TMP (TM4SF4), and enhanced expression of the corresponding gene in regenerating rat liver(1). In Biochimica et biophysica acta, 1518, 183-9. doi:. https://pubmed.ncbi.nlm.nih.gov/11267677/
3. Qiu, Jie, Liu, Zhanwu, Da, Liang, Li, Zaiping, Zhao, Mujun. 2006. Overexpression of the gene for transmembrane 4 superfamily member 4 accelerates liver damage in rats treated with CCl4. In Journal of hepatology, 46, 266-75. doi:. https://pubmed.ncbi.nlm.nih.gov/17069928/
4. Subramanian, Veedamali S, Nabokina, Svetlana M, Said, Hamid M. 2013. Association of TM4SF4 with the human thiamine transporter-2 in intestinal epithelial cells. In Digestive diseases and sciences, 59, 583-90. doi:10.1007/s10620-013-2952-y. https://pubmed.ncbi.nlm.nih.gov/24282057/
5. Mou, Yanjie, Ding, Xiaoming. 2022. LncRNA ST8SIA6-AS1 facilitates hepatocellular carcinoma progression by governing miR-651-5p/TM4SF4 axis. In Anti-cancer drugs, 33, 741-751. doi:10.1097/CAD.0000000000001326. https://pubmed.ncbi.nlm.nih.gov/35946523/
6. Jung, Kyungsoo, Choi, Joon-Seok, Koo, Beom-Mo, Oh, Doo-Yi, Choi, Yoon-La. 2020. TM4SF4 and LRRK2 Are Potential Therapeutic Targets in Lung and Breast Cancers through Outlier Analysis. In Cancer research and treatment, 53, 9-24. doi:10.4143/crt.2020.434. https://pubmed.ncbi.nlm.nih.gov/32972043/
7. Wang, Leiming, Feng, Jian, Da, Liang, Li, Zaiping, Zhao, Mujun. 2013. Adenovirus-mediated delivery of siRNA targeting TM4SF4 attenuated liver cancer cell growth in vitro and in vivo. In Acta biochimica et biophysica Sinica, 45, 213-9. doi:10.1093/abbs/gms115. https://pubmed.ncbi.nlm.nih.gov/23296076/
8. Li, Ying, Wang, Leiming, Qiu, Jie, Li, Zaiping, Zhao, Mujun. 2012. Human tetraspanin transmembrane 4 superfamily member 4 or intestinal and liver tetraspan membrane protein is overexpressed in hepatocellular carcinoma and accelerates tumor cell growth. In Acta biochimica et biophysica Sinica, 44, 224-32. doi:10.1093/abbs/gmr124. https://pubmed.ncbi.nlm.nih.gov/22236579/