Here we present different examples about how LAMP proteins can influence and support tumor growth and metastatic spread, emphasizing the impact of each single member of the family.
By restoring the expression of LSAMP in a cell line with a homozygous deletion of the gene, the proliferation rate in vitro was significantly reduced and tumor growth in vivo was significantly delayed.
Analysis of relapse samples identified recurrent MDRs at 3q13.31 (12.2%), 5q (4.9%), and 17p (4.9%), with the 3q13.31 region containing only LSAMP, a putative tumor suppressor.
Notably, these CNAs often involve the noncoding RNAs LOC285194 and BC040587 and, in some cases, a tumor suppressor gene that encodes the limbic system-associated membrane protein (LSAMP).
LSAMP showed low expression compared to two normal bone samples in 6/15 tumors and 5/9 cell lines with deletion of 3q13.31, and also in 5/14 tumors and 3/11 cell lines with normal copy number or gain.
This SNP genotyping study identified chromosomal aberrations associated with disease progression in OS and disclosed LSAMP as a novel tumor suppressor gene in OS.