The MIR3120 gene encodes a microRNA (miRNA) that plays an essential role in a variety of cellular processes. Here's a detailed explanation addressing your requests:

### 1. Associated Genes
MicroRNAs, including MIR3120, typically regulate multiple target genes. Although specific target genes for MIR3120 have not been explicitly mentioned in the summaries you provided, certain databases and literature reports may show associations with several genes involved in cellular processes such as apoptosis, proliferation, and development. To identify specific targets, bioinformatics tools like TargetScan or miRDB can be used. 

For illustrative purposes, some common miRNA targets include:
- **KRAS** (a gene involved in cellular signaling)
- **TP53** (tumor suppressor gene)
- **VEGFA** (vascular endothelial growth factor)

### 2. Aging and Age-Related Diseases
The role of miRNAs in aging is an emerging area. While specific information on MIR3120 in relation to aging is limited, it’s known that miRNAs can modulate several age-related pathways, including:
- Cellular senescence
- Inflammation
- Apoptosis

Imbalances in miRNA expression, including those related to the MIR family, may contribute to age-related diseases, including cancers and neurodegenerative diseases. Further research is typically required to understand MIR3120's association specifically with these conditions.

### 3. Drug Interactions
While specific drug interactions for MIR3120 might not be readily available, miRNAs can be involved in the response to various drug treatments. It's generally known that:
- **Chemotherapeutic agents** often have their efficacy influenced by the expression of certain miRNAs, including potentially MIR3120.
- **Antisense oligonucleotides** or **miRNA mimics/inhibitors** targeting specific miRNAs can be designed therapeutically, though specific drugs related to MIR3120 have not been detailed in common pharmacological databases.

### 4. Pathways and Biological Processes
MIR3120, like other miRNAs, participates in several biological processes, including:
- **Regulation of gene expression**: The primary function of miRNAs is to inhibit or downregulate gene expression post-transcriptionally.
- **Developmental processes**: MiRNAs play critical roles in cellular differentiation during development.
- **Cell cycle regulation**: Specific miRNAs can influence cell cycle progression and apoptosis.

Furthermore, miRNAs have been implicated in various signaling pathways, including the **Wnt pathway**, **TGF-beta signaling**, and other pathways related to cellular growth and development.

### Conclusion
MIR3120 is an important microRNA associated with regulating gene expression in various biological processes. While direct associations with other genes, drug interactions, and detailed implications in aging and age-related diseases require further research, a broad understanding of the functional landscape of miRNAs can provide insights into their critical roles in cellular and molecular biology. For the latest research findings and specific target interactions, it is advisable to consult the latest scientific literature and database updates.