Bone morphogenetic proteins (BMP) are members of the transforming growth factor β superfamily (TGF-β). BMPs are involved in tumourigenesis and disease progression of certain malignancies. To date, the role played by BMPs in gastric cancer (GC) remains largely unknown. In the present study, we systematically analysed the expression and clinical significance of BMP and BMP receptors (BMPR) in TCGA gastric cancer database and GEO database and explored the possible mechanism of action. BMP5 is reduced in gastric cancer tissues, while ACVRL1, ACVR1, TGFBR1, and BMPR2 were significantly increased in the gastric tumours. BMP3, ACVR1, TGFBR1, BMPR1B (also known as ALK6), TGFBR2 and BMPR2 were significantly associated with poorer overall survival of GC patients. A negative correlation was seen between BMP/BMPR and proliferation markers which was supported by their correlation with the cell cycle promoters and inhibitors. More interestingly, further analyses showed that BMPs and their receptors are positively correlated with matrix metalloproteinases (MMPs), epithelial mesenchymal transition (EMT) markers and stemness in GC. Furthermore, positive correlations were also frequently seen between BMP receptors and markers/regulators of angiogenesis and lymphangiogenesis in the gastric tumours. Taken together, these findings suggest that BMPs play dual roles in GC. They may inhibit proliferation of GC cells. On the other hand, they can also promote disease progression through a promotion of invasion, EMT and stemness. The elevated expression of BMP receptors in GC were also highly associated with tumour associated angiogenesis and lymphangiogenesis which facilitate tumour growth, expansion and spread.

骨形态发生蛋白（BMP）是转化生长因子β超家族（TGF-β）的成员。BMP参与肿瘤的发生和某些恶性肿瘤的进展。迄今为止，BMP在胃癌（GC）中所起的作用仍然未知。在本研究中，我们系统地分析了TCGA胃癌数据库和GEO数据库中BMP和BMP受体（BMPR）的表达及其临床意义，并探讨了可能的作用机理。BMP5在胃癌组织中减少，而ACVRL1，ACVR1，TGFBR1和BMPR2在胃肿瘤中显着增加。BMP3，ACVR1，TGFBR1，BMPR1B（也称为ALK6），TGFBR2和BMPR2与GC患者较差的总体生存率显着相关。BMP / BMPR与增殖标志物之间存在负相关性，这与它们与细胞周期启动子和抑制剂的相关性有关。更有趣的是，进一步的分析表明BMP及其受体与基质金属蛋白酶（MMP），上皮间质转化（EMT）标记和GC的干度呈正相关。此外，在胃肿瘤中，BMP受体与血管生成和淋巴管生成的标志物/调节剂之间也经常发现正相关。综上，这些发现表明BMP在GC中起双重作用。它们可能抑制GC细胞的增殖。另一方面，它们还可以通过促进侵袭，EMT和茎干来促进疾病进展。