Past

Esophageal cancer has the sixth highest cancer mortality in the world. A majority of esophageal adenocarcinomas occur in developed countries, and esophageal squamous carcinomas (ESCCs) predominate in low-income countries, especially in China, where 90% are squamous carcinomas.1 The 5-year mortality rate of ESCCs is 30–40%, and the current clinical treatment is mainly based on radiotherapy and chemotherapy.2 Small molecule drugs have been rapidly developed in recent years, but they are less selective for ESCCs.

Present

COL8A1 was screened by tissue microarrays as a significantly highly expressed molecule in ESCC tissues, even though it was a nonindependent factor. However, it was found through cell and animal experiments that COL8A1 could regulate the proliferation and invasion of ESCCs through PI3K/AKT pathway activation.3 Resultingly, we believe that COL8A1 is a tumor marker or a key regulator of pathogenesis in ESCCs that deserves further investigation.

Future

COL8A1 (collagen type VIII alpha 1 chain), a secreted protein, is a promising tumor-promoting molecule whose role in gastrointestinal digestive system tumors has been partially reported,4,5 but not in ESCC. COL8A1 is predominantly distributed in the interstitial space of the cells, so COL8A1-mediated invasion of ESCC may be mediated by COL8A1 through the regulating intercellular communication, EMT transformation, or cell junction effects. Therefore, COL8A1-mediated tumor invasion and migration is a future research direction.