Oestrogen receptor beta isoform expression in sporadic colorectal cancer, familial adenomatous polyposis and progressive stages of colorectal cancer.

ABSTRACT:

Background

Among the sex hormones, oestrogen may play a role in colorectal cancer, particularly in conjunction with oestrogen receptor-? (ER?). The expression of ER? isoform variants and their correlations with familial adenomatous polyposis (FAP) syndrome and sporadic colorectal carcinomas are poorly described.

Methods

This study aimed to investigate the expression levels of the ER?1, ER?2, ER?4 and ER?5 isoform variants using quantitative RT-PCR (921 analyses) in FAP, normal mucosa, adenomatous polyps and sporadic colorectal carcinomas.

Results

Decreased expression of ER? isoforms was identified in sporadic polyps and in sporadic colorectal cancer as well as in polyps from FAP syndrome patients compared with normal tissues (p < 0.001). In FAP patients, ER?1 and ER?5 isoforms showed significant down-expression in polyps (p < 0.001) compared with matched normal tissues. However, no differences were observed when sporadic colorectal carcinomas were compared to normal mucosa tissues. These findings suggest an association of the ER? isoform variants in individuals affected by germline mutations of the APC gene. Progressively decreased expression of ER? was found in polyps at early stages of low-grade dysplasia, followed by T1-T2 and T3-T4 tumours (p < 0.05). In sporadic colorectal cancer, the loss of expression was an independent predictor of recurrence, and ER?1 and ER?5 expression levels were associated with better disease-free survival (p = 0.002).

Conclusion

These findings may provide a better understanding of oestrogens and their potential preventive and therapeutic effects on sporadic colorectal cancer and cancers associated with FAP syndrome.

SUBMITTER: Stevanato Filho PR 

PROVIDER: S-EPMC5683223 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature