AT-101 acts as anti-proliferative and hormone suppressive agent in mouse pituitary corticotroph tumor cells

Gossypol enhances ponatinib's cytotoxicity against human hepatocellular carcinoma cells by involving cell cycle arrest, p-AKT/LC3II/p62, and Bcl2/caspase-3 pathways

Despite significant breakthroughs in frontline cancer research and chemotherapy for hepatocellular carcinoma (HCC), many of the suggested drugs have high toxic side effects and resistance, limiting their clinical utility. Exploring potential therapeutic targets or novel combinations with fewer side effects is therefore crucial in combating this dreadful disease. The current study aims to use a novel combination of ponatinib and gossypol against the HepG2 cell line. Cell survival, FGF19/FGFR4, apoptotic and autophagic cell death, and synergistic drug interactions were assessed in response to increasing concentrations of ponatinib and/or gossypol treatment. Research revealed that ponatinib (1.25-40 μM) and gossypol (2.5-80 μM) reduced the viability of HepG2 cells in a way that was dependent on both time and dose. Ponatinib's anti-proliferation effectiveness was improved synergistically by gossypol and was associated with a rise in apoptotic cell death, cell cycle blockage during the G0/G1 phase, and suppression of the FGF19/FGFR4 axis. Furthermore, the ponatinib/gossypol combination lowered Bcl-2 and p-Akt while increasing active caspase-3, Beclin-1, p62, and LC3II. This combination, however, had no harm on normal hepatocytes. Overall, gossypol enhanced ponatinib's anticancer effects in HCC cells. Notably, this new combination appears to be potential adjuvant targeted chemotherapy, a discovery that warrants more clinical investigation, in the management of patients with HCC.

Advances in mitophagy and mitochondrial apoptosis pathway-related drugs in glioblastoma treatment

Glioblastoma (GBM) is the most common malignant tumor of the central nervous system (CNS). It is a leading cause of death among patients with intracranial malignant tumors. GBM exhibits intra- and inter-tumor heterogeneity, leading to drug resistance and eventual tumor recurrence. Conventional treatments for GBM include maximum surgical resection of glioma tissue, temozolomide administration, and radiotherapy, but these methods do not effectively halt cancer progression. Therefore, development of novel methods for the treatment of GBM and identification of new therapeutic targets are urgently required. In recent years, studies have shown that drugs related to mitophagy and mitochondrial apoptosis pathways can promote the death of glioblastoma cells by inducing mitochondrial damage, impairing adenosine triphosphate (ATP) synthesis, and depleting large amounts of ATP. Some studies have also shown that modern nano-drug delivery technology targeting mitochondria can achieve better drug release and deeper tissue penetration, suggesting that mitochondria could be a new target for intervention and therapy. The combination of drugs targeting mitochondrial apoptosis and autophagy pathways with nanotechnology is a promising novel approach for treating GBM.This article reviews the current status of drug therapy for GBM, drugs targeting mitophagy and mitochondrial apoptosis pathways, the potential of mitochondria as a new target for GBM treatment, the latest developments pertaining to GBM treatment, and promising directions for future research.

The ponatinib/gossypol novel combination provides enhanced anticancer activity against murine solid Ehrlich carcinoma via triggering apoptosis and inhibiting proliferation/angiogenesis

The search for new antitumor agents or combinations that are more effective and, hopefully, provide fewer health hazards is ongoing. Therefore, this study investigated the efficacy of a novel combination of ponatinib, a multi-targeted tyrosine kinase inhibitor, and the natural phytochemical gossypol against murine solid Ehrlich carcinoma. Six groups of ten mice each received vehicle (I), ponatinib in doses of 10 and 15 mg/kg (II, III) respectively, gossypol in a dose of 4 mg/kg (IV), and ponatinib (10 or 15 mg/kg) in combination with gossypol (4 mg/kg; V, VI). All treatments started on the 12th post-Ehrlich ascites carcinoma (EAC) implantation day and were administered intraperitoneally in daily doses for 3 weeks. Treatment of EAC-bearing mice with ponatinib/gossypol combination improved anticancer efficacy over either drug alone, as demonstrated by greater decreases in tumor weight and volume, and ponatinib (10 mg/kg)/gossypol combination was more efficient than ponatinib (15 mg/kg). Mechanistically, the ponatinib/gossypol combination significantly increased apoptotic markers p53, Bax, and caspase-9 while decreasing anti-apoptotic marker Bcl-2. Furthermore, it greatly decreased proliferative and angiogenic markers, FGFR4 and VEGF, respectively. Histopathology revealed a significant decline in neoplastic cells, the majority of which have necrotic changes and numerous apoptotic bodies, as well as a decrease in mitotic figures and tumor giant cells, indicating the capacity to suppress cancer proliferation/persistence. Overall, gossypol could be used as an adjuvant medication for ponatinib in cancer treatment, possibly leading to successful dose reductions and fewer side effects; however, further research is needed before a clinical application could be feasible.

Endocrine disruptors of inhibiting testicular 3β-hydroxysteroid dehydrogenase

Testicular 3β-hydroxysteroid dehydrogenase (HSD3B) is a steroidogenic enzyme, catalyzing the conversion of 3β-hydroxysteroids into 3-keto-steroids. Two distinct isoforms in the human are cloned, HSD3B1 and HSD3B2, and HSD3B2 is located in the testis. HSD3B2 is a two-substrate enzyme, which binds to cofactor NAD⁺ and a 3β-steroid. Many endocrine disruptors, including industrial compounds (phthalates, bisphenols, and perfluoroalkyl substances), insecticides and biocides (organochlorine insecticides and organotins), food additives (butylated hydroxyanisole, resveratrol, gossypol, flavones, and isoflavones), and drugs (etomidate, troglitazone, medroxyprogesterone acetate, and ketoconazole) inhibit testicular HSD3B, possibly interfering with androgen synthesis. In this review, we discuss the distinct testicular isoform of HSD3B, its gene, chemistry, subcellular location, and the endocrine disruptors that directly inhibit testicular HSD3B and their inhibitory modes.

Effect of the BH3 Mimetic Polyphenol (-)-Gossypol (AT-101) on the in vitro and in vivo Growth of Malignant Mesothelioma

Malignant mesothelioma (MM) is a primary tumor arising from mesothelial cells. The survival of MM patients following traditional chemotherapy is poor, thus innovative treatments for MM are needed. (-)-gossypol (AT-101) is a BH3 mimetic compound which possesses anti-tumoral activity by targeting multiple signaling transduction pathways. Several clinical trials employing AT-101 have been performed and some of them are still ongoing. Accordingly, we investigated the in vitro effects of AT-101 on cell proliferation, cell cycle regulation, pro-survival signaling pathways, apoptosis and autophagy of human (MM-B1, H-Meso-1, and MM-F1) and mouse (#40a) MM cell lines. In addition, we explored the in vivo anti-tumor activities of AT-101 in a mouse model, in which the transplantation of MM cells induces ascites in the peritoneal space. AT-101 inhibited in vitro MM cells survival in a dose- and time-dependent manner and triggered autophagy, but the process was then blocked and was coincident with apoptosis activation. To confirm the effect of AT-101 in inducing the apoptosis of MM cells, MM cells were simultaneously treated with AT-101 and with the caspase inhibitor, Z-VAD-FMK. Z-VAD-FMK was able to significantly reduce the number of cells in the subG1 phase compared to the treatment with AT-101 alone. This result corroborates the induction of cell death by apoptosis following treatment with AT-101. Indeed, Western blotting results showed that AT-101 increases Bax/Bcl-2 ratio, modulates p53 expression, activates caspase 9 and the cleavage of PARP-1. In addition, the treatment with AT-101 was able to: (a) decrease the ErbB2 protein expression; (b) increase the EGFR protein expression; (c) affect the phosphorylation of ERK1/2, p38 and AKT; (d) stimulate JNK1/2 and c-jun phosphorylation. Our in vivo results showed that the intraperitoneal administration of AT-101 increased the median survival of C57BL/6 mice intraperitoneally transplanted with #40a cells and reduced the risk of developing tumors. Our findings may have important implications for the design of MM therapies by employing AT-101 as an anticancer agent in combination with standard therapies.