### SART1 Gene Overview:

**Gene Symbol:** SART1 

**Function and Protein Expression:**
The SART1 gene encodes two distinct proteins through different translational processes: 
- **SART1(800):** Primarily expressed in the nucleus of proliferating cells, involved in overall cellular regulation.
- **SART1(259):** Expressed in the cytosol, particularly relevant in epithelial cancers and produced via a -1 frameshifting mechanism during post-transcriptional regulation. It has been shown to induce HLA-A2402-restricted cytotoxic T lymphocytes, suggesting its potential role in cancer immunotherapy.

Both proteins function in the regulation of cellular proliferation and are implicated as tumor rejection antigens, reflecting their relevance in cancer biology. In addition, SART1(259) is essential for recruiting the tri-snRNP to the pre-spliceosome, indicating its role in mRNA splicing as part of the spliceosome assembly.

### 1. Associated Genes:
While the summaries do not specify precise associations with other genes, genes known to be involved in similar pathways (e.g., mRNA splicing and cancer) may include:
- **PRPF8:** Known for its role in spliceosome function.
- **SNRNP200:** Involved in the spliceosome assembly.
- **RBPMS:** A gene involved in RNA binding and splicing.
- **HLA genes:** As SART1(259) is associated with immune responses, it correlates with various HLA class genes.

### 2. Aging and Age-Related Diseases:
Recent studies have indicated that SART1 may be associated with:
- **Cellular Senescence:** Proteins involved in splicing often play roles in cellular senescence, a crucial factor in aging and age-related diseases.
- **Cancer:** Age is a significant risk factor for various cancers; as such, SART1's role in tumor rejection and immune response may elucidate mechanisms in oncogenesis in aged populations. Research into the roles of splicing factors like SART1 has suggested potential associations with age-related decline in immune function and increased cancer susceptibility.

### 3. Known Drug Interactions:
Currently, there are no well-established drugs or drug classes directly interacting with SART1. However, because it plays a role in mRNA splicing and tumor immunity, inhibitors of splicing (like **spliceostatin A**) or general oncology therapeutics (e.g., **immune checkpoint inhibitors**) could potentially intersect at pathways involving SART1. The use of cancer vaccines targeting SART1(259) is under exploration for therapeutic purposes.

### 4. Pathways and Biological Processes:
SART1 is involved in several key biological processes and pathways:
- **mRNA Splicing:** Functions as a component of the U4/U6-U5 tri-snRNP complex, critical in spliceosome assembly and function.
- **Cell Proliferation:** Participates in regulatory mechanisms of cellular growth and proliferation.
- **Antigen Processing and Presentation:** Particularly relevant due to the immunogenic potential of SART1(259) for T-cell responses.
- **Epithelial Cell Function:** Relevant in the pathology of epithelial cancers, linking SART1's activity to oncogenesis in these tissues.

### Summary:
SART1 is a multifaceted gene that plays a crucial role in cell proliferation and mRNA splicing, with significant implications for cancer immunotherapy and potential links to aging and age-related diseases. Its expression patterns and functional activities make it an important subject of research within the fields of oncology and molecular biology.