Targeting mitochondrial ribosomal protein expression by andrographolide and melatonin for colon cancer treatment.
Study Goal
The researchers aimed to investigate the effect of melatonin (MLT) in combination with andrographolide (AGP) on mitochondrial dynamics and the expression of mitochondrial ribosomal proteins in colon cancer stem cells (CSCs).
Results Summary
The study found that MLT and AGP synergistically reduced active mitochondrial mass, downregulated fusion and fission proteins, inhibited CSC growth via Nrf2/KEAP1 signaling, and significantly decreased MRPS6 expression, leading to reduced cell viability and colony formation.
Population
Colon cancer stem cells (CSCs) and xenograft models of colorectal cancer.
Effective Dosage
Not specified
Duration
Not specified
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
andrographolide (AGP) and melatonin (MLT) | decrease | total active mitochondrial mass | colon cancer stem cells (CSCs) | - | synergistically reduce | #1 |
andrographolide (AGP) and melatonin (MLT) | decrease | fusion and fission proteins | colon cancer stem cells (CSCs) | - | downregulate | #2 |
andrographolide (AGP) and melatonin (MLT) | decrease | OXPHOS proteins | colon cancer stem cells (CSCs) | - | reduce | #3 |
andrographolide (AGP) and melatonin (MLT) | decrease | CSC growth inhibition | colon cancer stem cells (CSCs) | - | lead to | #4 |
AGP and MLT combination | neutral | differentially expressed mRNAs | colon cancer stem cells (CSCs) | 4389 | revealed | #5 |
AGP + MLT treatment | decrease | MRPS6 | colon cancer stem cells (CSCs) | - | dramatically downregulated | #6 |
MRPS6 inhibition by siRNA | decrease | mCRC cell viability | mCRC cells | - | reduced | #7 |
AGP | neutral | MRPS6 | - | - | has direct physical interaction with | #8 |
AGP | increase | MRPS6 | - | - | increases the binding affinity of MLT to | #9 |
This drug combination | decrease | genes in the NRF2 (NFE2L2) pathway | CSCs | - | downregulated | #10 |
MRPS6 knockdown | decrease | colony formation | cells | - | significantly reduced | #11 |
AGP-MLT combination | decrease | MRPS6 expression | xenograft models | - | synergistically decreased | #12 |
AGP-MLT combination | increase | apoptosis | xenograft models | - | increased | #13 |
Colospheroids contain colon cancer stem cells (CSCs) that cause colorectal cancer metastasis (mCRC). Colorectal cancer (CRC) is the second leading cause of cancer-related deaths in the U.S. Little is known about the role of mitochondria in the survival and metastatic ability of CSCs. In this study, we investigate the effect of andrographolide (AGP) and melatonin (MLT) on mitochondrial dynamics (including fusion and fission) and the expression of mitochondrial ribosomal proteins (MRPs). Our results show that AGP and MLT synergistically reduce the total active mitochondrial mass, downregulate fusion and fission proteins, reduce OXPHOS proteins, and lead to CSC growth inhibition via Nrf2 and KEAP1 signaling. Microarray revealed 4389 differentially expressed mRNAs in the AGP and MLT combination compared to the control. Results exhibiting a three-fold induction/reduction were validated by qRT-PCR and immunoblot. MRPS6, a mitochondrial ribosomal (Mitoribosome) small subunit protein, was dramatically downregulated by AGP + MLT treatment compared to control. MRPS6 inhibition by siRNA reduced mCRC cell viability. Molecular docking-based protein-ligand interactions showed that AGP has direct physical interaction with MRPS6 and increases the binding affinity of MLT to MRPS6. This drug combination downregulated genes in the NRF2 (NFE2L2) pathway in CSCs. MRPS6 may be directly linked to CSC proliferation and could be a therapeutic target for this population. Functionally, MRPS6 knockdown significantly reduced colony formation, with enhanced suppression in AGP + MLT-treated cells. In xenograft models, the AGP-MLT combination synergistically decreased MRPS6 expression and increased apoptosis, as evidenced by TUNEL assays, demonstrating the therapeutic potential of targeting MRPS6 in CRC.