| Gene information | Literature | Expression | lncRNA | Mutation | Homolog |
Basic Information | |
|---|---|
Gene ID | 27257 |
Name | LSM1 |
Synonymous | LSM1, U6 small nuclear RNA associated;LSM1;LSM1, U6 small nuclear RNA associated |
Definition | LSM1 homolog, U6 small nuclear RNA associated|U6 snRNA-associated Sm-like protein LSm1|cancer-associated Sm-like protein|small nuclear ribonuclear CaSm |
Position | 8p11.2 |
Gene type | protein-coding |
Title | Abstract |
| Transforming function of the LSM1 oncogene in human breast cancers with the 8p11-12 amplicon. | Amplification of the 8p11-12 region occurs in 15-20% of breast cancers, but the driving oncogene at this locus has yet to be definitively identified. We mapped the 8p11-12 amplicon in breast cancer cell lines and primary human breast cancers and identified the candidate oncogene human Sm-like protein (hLsm1, LSM1) based on increases in copy number and expression level relative to human mammary epithelial cells. To examine the oncogenic role of LSM1, we overexpressed this gene in MCF10A mammary epithelial cells and inhibited its production in the SUM44 breast cancer cell line, which has a natural amplification and overexpression of LSM1. Our data confirmed that LSM1 is an oncogene from the 8p11-12 amplicon by showing that hLsm1 overexpression induced growth factor-independent proliferation and soft agar colony formation in MCF10A cells, and hLsm1 inhibition in SUM44 cells dramatically reduced soft agar growth. Little is known about hLsm1 function other than its involvement in mRNA degradation; therefore, we used expression microarray analysis to investigate how hLsm1 affects cell transformation in MCF10A and SUM44 cells. We identified numerous genes altered following hLsm1 overexpression common to SUM44 breast cancer cells that play important roles in cell cycle regulation, cell proliferation and other cancer-promoting processes. Future work will continue to characterize these important changes to achieve a more complete understanding of the mechanism of hLsm1 s effect on cancer progression. |
| CaSm (LSm-1) overexpression in lung cancer and mesothelioma is required for transformed phenotypes. | CaSm (cancer-associated Sm-like) was originally identified based on elevated expression in pancreatic cancer and in several cancer-derived cell lines. It encodes a 133-amino acid protein that contains two Sm motifs found in the common snRNP proteins and the LSm (like-Sm) family of proteins. Lung tumors and mesotheliomas express high levels of CaSm mRNA and protein compared with adjacent nontumor and normal lung tissue, measured by immunohistochemistry, qRT-PCR, and Western blot analyses. In addition, several human lung cancer- and mesothelioma-derived cell lines have elevated CaSm expression. Two cell lines, transfected with and expressing antisense CaSm RNA, demonstrate altered transformed phenotypes, reducing their ability to form colonies in soft agar and tumors in SCID mice. Furthermore, RNAi-mediated reduction of CaSm RNA and protein is associated with inhibition of cellular growth. These data support the model that elevated CaSm expression in epithelial tissue contributes to the transformed state. Cell lines expressing exogenous CaSm also exhibit transformed characteristics, including increased anchorage-independent colony formation and tumor growth. Thus, the results of loss of function and gain of function studies presented both indicate that CaSm functions as an oncogene in the promotion of cellular transformation and cancer progression. |