Glutathione S-transferases (GSTs) are a family of phase II detoxification enzymes that play key roles in catalyzing the conjugation of glutathione (GSH) to a wide range of electrophilic compounds. This family includes multiple isoenzymes (e.g., GST-α, GST-μ, GST-π) with tissue-specific expression patterns and overlapping as well as distinct substrate specificities.
-GSTs are important for detoxifying potentially harmful compounds, including products of oxidative stress, environmental toxins, and chemotherapeutic agents.
-They contribute to the cellular defense mechanism against oxidative damage and help maintain cellular redox balance.
-Beyond detoxification, GSTs can modulate cell signaling pathways, potentially affecting cell proliferation, apoptosis, and drug resistance.
-GST-π is commonly upregulated in several cancers such as breast, lung, colorectal, and hematologic malignancies.
-Elevated expression of specific GST isoenzymes—most notably GST-π—has been associated with a poorer prognosis in several cancer types. This is often linked to resistance to chemo- or radiotherapy, as higher GST activity can lead to more efficient detoxification of these agents, reducing their cytotoxic effects.
-In contrast, reduced GST expression in some contexts might indicate a less robust detoxification system, which can correlate with increased sensitivity to oxidative stress and possibly a less aggressive tumor phenotype.
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