Given an abstract from a research paper, your task is to identify and label relationships between chemical compounds and genes mentioned in the abstract.

The relationship type must be one of ['DOWNREGULATOR', 'SUBSTRATE', 'INDIRECT-REGULATOR', 'PART-OF', 'MODULATOR-ACTIVATOR', 'REGULATOR', 'INHIBITOR', 'COFACTOR', 'UPREGULATOR', 'ACTIVATOR', 'ANTAGONIST', 'NOT', 'INDIRECT-DOWNREGULATOR', 'SUBSTRATE_PRODUCT-OF', 'INDIRECT-UPREGULATOR', 'AGONIST', 'PRODUCT-OF', 'MODULATOR', 'DIRECT-REGULATOR', 'UNDEFINED', 'AGONIST-INHIBITOR', 'AGONIST-ACTIVATOR', 'MODULATOR-INHIBITOR'].

Please format your output as a JSON array. Each entry in the array should express a single relation, formatted as ["<Entity_A>", "<RELATION_A_B>", "<Entity_B>"]. If no relations can be found, please output an empty JSON array [].

Abstract:

Overexpression of proline oxidase induces proline-dependent and mitochondria-mediated apoptosis. Proline oxidase (POX), a mitochondrial inner-membrane protein, catalyzes the rate-limiting oxidation of proline to pyrroline- 5-carboxylate (P5C). Previously we showed that overexpression of POX is associated with generation of reactive oxygen species (ROS) and apoptosis in POX-inducible colorectal cancer cells, DLD-1.POX. We also showed expression of mitochondrial MnSOD partially blunts POX-induced ROS generation and apoptosis. To further investigate the molecular basis of POX-induced apoptosis, we utilized the DLD-1.POX cells to show that cells overproducing POX exhibit an L-proline-dependent apoptotic response. The apoptotic effect is specific for L-proline, detectable at 0.2 mM, maximal at 1 mM, and occurs during 48-72 h following the addition of L-proline to cells with maximally induced POX. The apoptotic response is mitochondria-mediated with release of cytochrome c, activation of caspase-9, chromatin condensation/DNA fragmentation, and cell shrinkage. We conclude that in the presence of proline, high POX activity is sufficient to induce mitochondria-mediated apoptosis.
[["proline", "SUBSTRATE", "POX"], ["pyrroline- 5-carboxylate", "PRODUCT-OF", "POX"], ["proline", "SUBSTRATE", "Proline oxidase"], ["P5C", "PRODUCT-OF", "POX"], ["P5C", "PRODUCT-OF", "Proline oxidase"], ["pyrroline- 5-carboxylate", "PRODUCT-OF", "Proline oxidase"], ["L-proline", "SUBSTRATE", "POX"]]