Published online Oct 1, 1995. doi: 10.3748/wjg.v1.i1.21
Revised: June 20, 1995
Accepted: August 12, 1995
Published online: October 1, 1995
AIM: To evaluate the role and analyze the loss of heterozygosity (LOH) of adenomatous polyposis coli (APC), mutation in colorectal cancer (MCC) and deleted in colorectal cancer (DCC) genes in the development and progression of colorectal cancers.
METHODS: LOH at APC, MCC and DCC genes was examined in 41 surgically resected specimens of colorectal carcinomas by polymerase chain reaction and restriction fragment length polymorphism analysis technique.
RESULTS: LOH of APC and MCC were observed in 7 of 25 (28.0%) and 8 of 22 (36.4%) of informative cases, respectively. When considered as one locus, the LOH frequency for APC/MCC was 14 of 36 (38.9%). LOH at DCC gene locus was detected in 21 of 38 (55.3%) of informative cases. No correlation was found between the LOH at APC or MCC gene and tumor histological types, size, invasion, lymph node metastasis and Dukes’ stages (P > 0.05). However, LOH rates at DCC locus in the group with lymph-node metastasis (80.0%) and in Dukes’ stages III and IV (71.4%) were significantly higher than those without lymph node metastasis (39.1%) and in Dukes’ stages I and II (35.3%) (P < 0.05).
CONCLUSION: LOH at APC and/or MCC may occur more frequently in the early stages and plays a role in the initiation of colorectal cancer while LOH at DCC is frequent at late event and associated with the progression and metastasis of colorectal cancer.