Transmembrane 4 L Six Family, Member 5 (TM4SF5)

Like other TM4SF proteins, TM4SF5 is cysteine-rich. TM4SF5 shares 50% amino acid identity with the tumor-associated antigen L6 (TM4SF1). Northern blot analysis of various normal human tissues, namely intestine, pancreas, stomach, colon, esophagus, bladder, uterus, placenta, and adipose tissue, detected TM4SF5 expression only in intestine and 1 of 14 pancreas samples. TM4SF5 was overexpressed in 13 of 14 pancreatic adenocarcinomas, as compared with both normal pancreatic and chronic pancreatitis tissues. TM4SF5 expression was also found in 2 of 2 gastric cancers, 1 of 2 colon carcinomas, 1 of 1 carcinoma of the papilla vateri, and 1 of 1 soft-tissue sarcoma. TM4SF5 was expressed as an approximately 1-kb transcript in the pancreatic tumors.