Pitfalls and other issues with the MTT assay.

Area of Science:

• Biochemistry
• Cell Biology
• Cancer Research

Background:

• The MTT assay is frequently used to evaluate cellular response to treatments, including photodamage.
• This assay measures mitochondrial enzyme activity as an indicator of cell viability.
• Its correlation with tumor eradication, the primary goal of anti-tumor therapy, is often assumed but not rigorously validated.

Discussion:

• This study critically analyzes the reliability of the MTT assay in cancer research.
• Data from MTT assays showed a lack of correlation with results from clonogenic assays, a more established measure of cell survival and reproductive integrity.
• The term 'cytotoxicity' derived from MTT assays is ill-defined and does not necessarily reflect the potential for tumor eradication.

Key Insights:

• MTT assay results for photodamage effects on mitochondrial enzymes do not correlate with clonogenic assay outcomes.
• The MTT assay's measure of 'cytotoxicity' is not reliably linked to tumor eradication, the key objective in anti-tumor therapy.
• Consequently, the MTT assay is deemed an unreliable method for assessing treatment effects on cell viability in this context.

Outlook:

• Further research is needed to identify and validate more reliable assays for assessing anti-tumor treatment efficacy.
• Re-evaluation of standard laboratory practices regarding the use of the MTT assay in cancer research is recommended.
• Developing assays that directly measure tumor eradication potential is crucial for advancing cancer therapy evaluation.