active cysteine-aspartic acid protease 3

Overview

Active cysteine-aspartic acid protease 3 is the activated form of caspase-3, a key executioner protease in the apoptotic cascade. As a cysteine-dependent aspartate-specific protease, it is typically generated by proteolytic cleavage of the inactive precursor and functions downstream of intrinsic and extrinsic cell-death signaling. Once activated, it cleaves multiple structural and regulatory substrates, including PARP and gasdermin family proteins, thereby promoting apoptosis and, in some contexts, pyroptosis-like inflammatory cell death.

In biomedical research, active caspase-3 is widely used as a marker of apoptosis and treatment response in cancer, neurodegeneration, toxicology, and tissue injury models. It is frequently studied alongside B-cell lymphoma 2 (BCL2), Bax, cytochrome c, caspase-8, caspase-9, TP53, and Gasdermin E, reflecting its position at the convergence of mitochondrial apoptosis, stress signaling, and immunogenic cell death pathways.

Focus of Latest Publications

Recent publications have used active cysteine-aspartic acid protease 3 primarily as a readout of apoptosis and, in some cases, as a mechanistic node connecting apoptosis to inflammatory cell death.

In cancer research, multiple studies reported increased caspase-3 activation after treatment with candidate therapeutics. A PD-L1-targeted cisplatin prodrug (MN42-81) was described as downregulating PD-L1 and Bcl-2 while activating caspase-3, consistent with induction of tumor cell apoptosis. Similarly, santamarine combined with cisplatin in oral cancer cells increased annexin V positivity and activated caspase-3, caspase-8, and caspase-9, alongside ROS accumulation, JNK signaling, and DNA damage markers such as γH2AX and 8-OHdG. In colorectal carcinoma models, dual EGFR/CDK-2 inhibitors induced G2/M arrest and apoptosis with upregulation of Bax, cytochrome c, and caspase-3 and downregulation of AKT-1 and Bcl-2. Other anticancer studies reported caspase-3 activation in hepatocellular carcinoma, nasopharyngeal carcinoma, lung adenocarcinoma, and prostate cancer models, including sophocarpine derivatives, tetrahydroberberine, rBmTI-6, urolithin derivatives, and chalcone analogues. These findings collectively position active caspase-3 as a common endpoint of mitochondrial apoptosis in tumor cells.

Several studies linked active caspase-3 to immunogenic or lytic cell death. In triple-negative breast cancer, ER-targeting NIR cyanine nanoparticles promoted pyroptosis through cleavage of caspase-3 and GSDME, accompanied by LDH release and inflammatory cytokines such as IL-1β and IL-18. A related immunotherapy study reported that pan-PKC inhibition overcame anti-PD-1 resistance by inducing caspase-3/GSDME-dependent immunogenic pyroptotic cell death, improving tumor-intrinsic PD-L1 degradation via GSK3β and enhancing CD8+ T cell recruitment through CCL4-CCR5 signaling. Another photodynamic immunotherapy study found that hydroxyl radical generation from an iridium(III)-based photosensitizer induced PANoptosis, with increased cleaved caspase-3, GSDMD-N, and p-MLKL, indicating simultaneous engagement of apoptotic, pyroptotic, and necroptotic pathways. These reports show that active caspase-3 is not only an apoptosis marker but also a mediator of cross-talk with gasdermin-dependent inflammatory death.

In nonmalignant systems, active caspase-3 was used to assess protection against cell injury or degeneration. In a rat model of Huntington’s disease, pinostrobin was evaluated for effects on programmed cell-death markers including caspase-3 and caspase-9 in striatal tissue. In a cuprizone-induced demyelination model, roflumilast was associated with reduced caspase-3 in oligodendrocytes, consistent with diminished apoptosis during remyelination. Genistein-3'-sodium sulfonate reduced caspase-3 expression in a chronic cerebral hypoperfusion model, alongside lower IBA-1, iNOS, NF-κB p65, and IL-1β, suggesting attenuation of neuroinflammation and blood-brain barrier dysfunction. FuBIG also suppressed neuronal apoptosis by modulating Bcl-2, Bax, and caspase-3 in diabetic neuroinflammation. In developmental and toxicology contexts, increased caspase-3 labeling was reported in ameloblasts after fluoride and amoxicillin exposure, and in placental tissue from diabetic gestation models, indicating apoptosis-associated tissue injury.

Active caspase-3 was also used in studies of metabolic or inflammatory injury. In acute liver failure, α-linolenic acid-driven nano-liposomes were evaluated alongside p-JAK2/p-STAT3, TP53, Bcl-2, and active caspase-3, suggesting involvement of mitochondrial apoptosis in hepatoprotection. In eryptosis research, however, caspase-3 inhibition did not affect tobacco heating product aerosol-induced phosphatidylserine externalization, implying that some cell death phenotypes may proceed independently of caspase-3. Across these studies, active caspase-3 served as a key indicator of whether interventions promoted survival, apoptosis, or inflammatory cell death.

Key Publications

• NEWJun Reversing immunotherapy resistance in cold tumors by weaponizing pyroptosis with a dual-payload nanotuner. (Journal of controlled release : official journal of the Controlled Release Society, 2026, PMID 42314991): "...that directly activate caspase-3, cleaving GSDME to initiate non-canonical pyroptosis."
• Jun Heteronemin suppresses chemoresistant oral squamous cell carcinoma cells through ROS-mediated apoptosis and cuproptosis-associated mitochondrial stress. (Apoptosis : an international journal on programmed cell death, 2026, PMID 42315805): "HET triggered intrinsic apoptosis, characterized by mitochondrial depolarization, upregulated cleaved caspase-3/PARP and Bax, and downregulated Bcl-2."
• Jun A β‑1,3‑1,6‑glucan from Aureobasidium pullulans enhances apoptotic and autophagic pathways in colorectal cancer cells. (Molecular medicine reports, 2026, PMID 42318971): "Apoptotic cell death was evidenced by increased caspase-3/7 enzymatic activity and proteolytic cleavage of caspase-3, -7, -8, -9 and poly (ADP-ribose) polymerase."
• Jun Synthesis and evaluation of Urolithins derivatives as anticancer agents for hepatocellular carcinoma: In vitro, molecular docking, and dynamics simulations. (Bioorganic chemistry, 2026, PMID 41855633): "Moreover, integrated network pharmacology and molecular docking analyses identified several key targets, including EGFR, AKT1, MAPK1, and CASP3, suggesting a multi-target mechanism involving regulation of the PI3K/Akt and MAPK signaling pathways."
• Jun Discovery of triazole analogues as selective IDO1 inhibitors: Dual mechanistic effects on kynurenine pathway suppression and apoptosis in cancer cells. (Bioorganic chemistry, 2026, PMID 41856068): "the mechanism of cytotoxicity was studied through apoptosis, as evidenced by increased levels of cytochrome c, caspase-3, caspase-9, caspase-8 (excluding), and PARP-1 in HepG2 cells."
• Jun Kunitz-type serine protease inhibitor rBmTI-6 as a potential therapeutic lead for lung adenocarcinoma. (Biochemical and biophysical research communications, 2026, PMID 41966745): "Mechanistic analyses revealed activation of caspase-3 and a progressive increase in apoptotic cell populations, indicating that rBmTI-6 primarily induces caspase-dependent apoptosis in tumor cells."
• Jun Composite nanovesicles for enhanced chemodynamic cancer therapy via decitabine-mediated epigenetic reactivation. (Journal of controlled release : official journal of the Controlled Release Society, 2026, PMID 41871782): "Meanwhile, activation of the intrinsic apoptotic pathway induces caspase-3 cleavage of gasdermin E (GSDME), thereby inducing pyroptosis."
• Jun Targeting XIAP-coordinated PKC signaling resensitizes PD-1-refractory tumors for rechallenge. (Proceedings of the National Academy of Sciences of the United States of America, 2026, PMID 42234523): "Pan-PKC inhibition overcomes anti-PD-1 resistance by inducing Caspase-3/GSDME-dependent immunogenic pyroptotic cell death, promoting tumor-intrinsic PD-L1 degradation via GSK3β activation, and enhancing CD8+ T cell recruitment and effector function through tumor-derived CCL4-CCR5 signaling."
• Jun Synthesis, and pharmacological evaluation of iminoguanidine derivatives: Identification of FuBIG showing protective effects against diabetic neuroinflammation with a favorable lactate metabolism profile. (European journal of medicinal chemistry, 2026, PMID 41911662): "FuBIG inhibited neuronal apoptosis by up-regulating anti-apoptotic protein Bcl-2 and down-regulating pro-apoptotic proteins Bax and Caspase-3."
• Jun Hydroxyl radical from iridium(III)-based photosensitizer triggers PANoptosis and ferroptosis for hypoxia-tolerant photodynamic immunotherapy. (Bioorganic chemistry, 2026, PMID 41702130): "Mechanistically, the •OH produced by Ir1 induced PANoptosis by increasing the expression of cleaved Caspase-3, GSDMD-N, and p-MLKL, and activated ferroptosis through the GSH-GPX4-LPO axis."