LAPTM4B allele *2 is associated with breast cancer susceptibility and prognosis.

BACKGROUND

Lysosome-associated protein transmembrane 4 beta (LAPTM4B) has two alleles named LAPTM4B1 and LAPTM4B2. Allele 1 contains only one copy of a 19-bp sequence at the 5'UTR in the first exon, whereas this sequence of allele2 is duplicated and arrayed as a tandem repeat. Previous studies revealed that LAPTM4B polymorphisms contribute to the risk of certain types of cancers. This study aimed to investigate the polymorphism of LAPTM4B in breast cancer by analysis the correlation of LAPTM4B genotype with breast cancer susceptibility, clinicopathologic features and prognosis.

METHODS

Genotyping of the LAPTM4B polymorphism was determined by PCR method. The expression levels of LAPTM4B in breast cancer tissues and breast cancer cell lines were determined by quantitative reverse-transcription PCR (qRT-PCR) analysis. The correlation of LAPTM4B genotype with clinicopathologic parameters and prognosis were assessed statistically.

RESULTS

The results of qRT-PCR analysis indicated that LAPTM4B2 was associated with the higher level of LAPTM4B expression compared with the LAPTM4B1 in both breast cancer cell lines and breast cancer tissues. We found that LAPTM4B2 was associated with an increased risk for breast cancer. LAPTM4B2 was significantly associated with higher histopathologic grade, lymph node metastasis and poor prognosis.

CONCLUSION

LAPTM4B2 is a risk factor associated with breast cancer susceptibility and poor prognosis. LAPTM4B2 may be a potential predicative marker for the susceptibility, progression and metastasis of breast cancer.