### CASC3 Gene Overview

**Gene Symbol:** CASC3  
**Function:** CASC3 encodes a core component of the exon junction complex (EJC), involved in various aspects of mRNA metabolism including export, localization, translation, and nonsense-mediated decay (NMD). It plays a critical role in processing spliced mRNA and maintaining transcript fidelity.

### Associated Genes

CASC3 is known to interact with several other genes and proteins that participate in mRNA metabolism and splicing. Notably:

- **EIF4A3:** The EJC component that interacts with CASC3 and has ATPase and RNA helicase activities.
- **UPF2 and UPF3:** These are involved in the NMD pathway, along with CASC3, indicating a collaborative role in RNA surveillance mechanisms.
- **SNRNP proteins:** Components of the spliceosome that work in conjunction with CASC3 during pre-mRNA splicing.

### Aging and Age-Related Diseases

CASC3 has been implicated in various age-related biological processes:

- **Cellular Stress Response:** CASC3 is involved in assembling stress granules, which may influence cell recovery and survival under stress, particularly relevant in aging where oxidative stress is enhanced.
- **Neurodegeneration:** Altered mRNA metabolism is associated with neurodegenerative diseases such as Alzheimer's, and CASC3’s role in dendritic ribonucleoprotein particles may connect it to synaptic function and plasticity, both of which can decline with aging.
- **Cancer:** Dysregulation of CASC3 could thus be linked to cellular transformations observed during aging and in age-related malignancies, further suggesting its involvement in maintaining genomic integrity.

### Drug Interactions

While specific drugs directly targeting CASC3 are not well established, its involvement in critical pathways suggests potential interactions with:

- **Nonsense-Mediated Decay Modulators:** Compounds designed to enhance mRNA decay pathways could indirectly impact CASC3 activity.
- **RNA-targeting Therapies:** Drugs that aim to stabilize or alter RNA processing (e.g., some antisense oligonucleotides) may interact with its functions and pathways.

### Pathways and Biological Processes

CASC3 is involved in several key biological processes and pathways:

1. **mRNA Metabolism:**
   - Spliceosome assembly and function.
   - Exon junction complex formation and dynamics.
   - RNA localization and export.

2. **Nonsense-Mediated Decay (NMD):**
   - Participates in the surveillance of transcripts containing premature stop codons.

3. **Stress Response Mechanisms:**
   - Assembly of cytoplasmic stress granules.
   - Mediating cell response to various stressors.

4. **Cellular Localization Processes:**
   - May aid in the transport and localization of mRNA within neurons, impacting synaptic function and plasticity.

In summary, CASC3 plays a vital role in the post-transcriptional regulation of mRNA, associated with multiple interacting proteins, impacting aging and stress responses, and shows relevance in various mRNA-related processes and potential therapeutic interactions.