Proxalutamide reduces SARS-CoV-2 infection and associated inflammatory response.

Early in the COVID-19 pandemic, data suggested that males had a higher risk of developing severe disease and that androgen deprivation therapy might be associated with protection. Combined with the fact that TMPRSS2 (transmembrane serine protease 2), a host entry factor for the SARS-CoV-2 virus, was a well-known androgen-regulated gene, this led to an upsurge of research investigating androgen receptor (AR)-targeting drugs. Proxalutamide, an AR antagonist, was shown in initial clinical studies to benefit COVID-19 patients; however, further validation is needed as one study was retracted. Due to continued interest in proxalutamide, which is in phase 3 trials, we examined its ability to impact SARS-CoV-2 infection and downstream inflammatory responses. Proxalutamide exerted similar effects as enzalutamide, an AR antagonist prescribed for advanced prostate cancer, in decreasing AR signaling and expression of TMPRSS2 and angiotensin-converting enzyme 2 (ACE2), the SARS-CoV-2 receptor. However, proxalutamide led to degradation of AR protein, which was not observed with enzalutamide. Proxalutamide inhibited SARS-CoV-2 infection with an IC50 value of 97 nM, compared to 281 nM for enzalutamide. Importantly, proxalutamide inhibited infection by multiple SARS-CoV-2 variants and synergized with remdesivir. Proxalutamide protected against cell death in response to tumor necrosis factor alpha and interferon gamma, and overall survival of mice was increased with proxalutamide treatment prior to cytokine exposure. Mechanistically, we found that proxalutamide increased levels of NRF2, an essential transcription factor that mediates antioxidant responses, and decreased lung inflammation. These data provide compelling evidence that proxalutamide can prevent SARS-CoV-2 infection and cytokine-induced lung damage, suggesting that promising clinical data may emerge from ongoing phase 3 trials.

Activity of preclinical and phase I clinical trial of a novel androgen receptor antagonist GT0918 in metastatic breast cancer.

PURPOSE: To evaluate GT0918, a 2nd-generation AR antagonist, for its AR down-regulation activity among breast cancer patients. METHODS: The effect of GT0918 on AR protein expression was evaluated in AR expression breast cancer cells and in breast cancer xenograft model. A 3 + 3 phase I dose-escalation study was launched in Peking University Cancer Hospital. The endpoints included dose finding, safety, pharmacokinetics, and antitumor activity. RESULTS: GT0918 was demonstrated to effectively suppress the expression of AR protein and the growth of AR-positive breast cancer tumors in mouse xenograft tumor models. All patients treated with GT0918 were at a QD dose-escalation of five dose levels from 100 to 500 mg. The most common treatment-related AEs of any grade were asthenia, anemia, decreased appetite, increased blood cholesterol, increased blood triglycerides, decreased white blood cell count, and increased low-density lipoprotein. Grade 3 AEs were fatigue (2 of 18, 11.1%), aspartate aminotransferase increase (1 of 18, 5.6%), alanine aminotransferase increase (1 of 18, 5.6%), and neutrophil count decrease (1 of 18, 5.6%). Clinical benefit rate (CBR) in 16 weeks was 23.1% (3/13). Among 7 AR-positive patients, 6 can evaluate efficacy, and 2 completed 23.5- and 25-cycle treatment, respectively (as of 2020/1/20). PK parameters showed a fast absorption profile of GT0918 in the single-dose study. GT0918 and its major metabolite reached steady-state serum concentration levels at day 21 after multiple dosing. CONCLUSION: GT0918 can effectively inhibit AR-positive breast cancer tumor growth. GT0918 was demonstrated well tolerated with a favorable PK profile. The suitable dose of GT0918 was 500 mg QD and may provide clinical benefits for AR-positive mBC.

Preclinical profile and phase I clinical trial of a novel androgen receptor antagonist GT0918 in castration-resistant prostate cancer.

PURPOSE: We conducted preclinical experiments and phase I clinical trial to investigate the safety, pharmacokinetics (PK) and antitumour effects of GT0918 in castration-resistant prostate cancer (CRPC). EXPERIMENTAL DESIGN: An androgen receptor (AR) competitive binding assay was performed, followed by evaluation of GT0918 on AR protein expression. The efficacy of GT0918 was investigated in a castration-resistant xenograft model. A phase I dose-escalation study of GT0918 in CRPC was also carried out to evaluate its safety, PK and antitumour efficacy. RESULTS: GT0918 was demonstrated to inhibit the binding of androgen to AR more potently than MDV3100, and to effectively reduce the AR protein level. GT0918 inhibited the transcriptional activity of wild-type AR and AR with clinically relevant ligand-binding domain mutations. Furthermore, GT0918 significantly inhibited the growth of prostate cancer. A total of 16 patients was treated with GT0918 at five dose levels. Among these 16 patients, 10 and 2 patients, respectively, completed a three-cycle and six-cycle treatment, in which MTD was not reached. All the treatment-related adverse events were grade I, including hypercholesterolemia, hypertriglyceridemia, fatigue and anaemia. PK parameters showed that drug exposure increased with dose proportionally from 50 to 300 mg and a saturation was observed between 300 and 400 mg. PSA declines of ≥30% and ≥50% were, respectively, observed in six and two cases. All the 12 patients with metastatic soft tissue lesions confirmed stable disease. CONCLUSIONS: GT0918, a full AR antagonist without agonist effect, has high binding affinity to AR with AR protein down-regulation activity. GT0918 is demonstrated to be well tolerated with a favourable PK profile and exhibits promising antitumour activity in CRPC. CLINICALTRIALS: gov identifier CTR20150501.

An ethyl acetate fraction of Artemisia capillaris (ACE-63) induced apoptosis and anti-angiogenesis via inhibition of PI3K/AKT signaling in hepatocellular carcinoma.

In cancer treatment, herbal medicines may be a good choice because of the reduced risk of adverse side effects. Artemisia capillaris has been recognized as a promising candidate due to its hepatoprotective effects. Herein, we investigated whether A. capillaris-derived fraction (ACE-63) could inhibit the progression of hepatocellular carcinoma (HCC) and its underlying mechanism. In this study, ACE-63 effectively inhibited the growth and proliferation of HCC cells. ACE-63 induced apoptosis, as observed using Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, which was accompanied with increases in cleaved Poly (ADP-ribose) polymerase (PARP) and caspase-3 in HCC cells. Additionally, the pro-apoptotic effect of ACE-63 was demonstrated by a decrease in the expression of the X-linked inhibitor of apoptosis protein (XIAP) and survivin via a loss of mitochondrial membrane potential. In an ex vivo model, ACE-63 significantly inhibited tumor cell growth and induced apoptosis by increasing the expression of cleaved caspase-3 and DNA fragmentation. In addition, ACE-63 decreased the expression of hypoxia-inducible factor-1α and vascular endothelial growth factor and inhibited tube formation of human umbilical vein endothelial cells. A mechanistic study revealed that ACE-63 effectively suppressed the PI3K/AKT/mTOR signaling pathways, which were observed as a target signaling by phosphokinase array. Taken together, our findings demonstrate that ACE-63 could not only efficiently induce apoptosis but also inhibit the growth/angiogenesis of human HCC cells by blocking the PI3K/AKT/mTOR signaling pathway, suggesting that ACE-63 may be a new chemotherapeutic candidate against HCC.

Artemisia capillaris extract AC68 induces apoptosis of hepatocellular carcinoma by blocking the PI3K/AKT pathway.

Artemisia capillaris Thunberg (AC) has been widely used to treat various diseases including hepatitis and is known to affect many cellular events such as cell proliferation and apoptosis. Herein a potent ethyl acetate fraction (AC68) was newly extracted from AC, and was assessed for its anti-cancer efficacy in progression and growth of hepatocellular carcinoma (HCC). AC68 dose-dependently inhibited the growth and proliferation of two HCC cell lines. The AC68-induced apoptosis was observed by increased levels of cleaved caspase-3 and decreased survivin, XIAP, and MCL-1 expression via mitochondria membrane potential change, as well as elevated numbers of TUNEL-positive apoptotic cells. AC68 was also found to suppress invasion and migration of HCC cells. Moreover, it inhibited PI3K/AKT signaling pathway in vitro and in vivo. In vivo study showed that AC68 significantly inhibited tumor growth in HCC mouse xenograft model, and induced apoptosis by increasing the expression of cleaved caspase-3. The expression of PCNA was decreased by the treatment of AC68. Taken together, our data demonstrated that AC68 not only induced apoptosis but also inhibited cell growth, migration, and invasion of liver cancer cells by blocking the PI3K/AKT pathway. We suggest that AC68 may be a potent chemotherapeutic candidate for the treatment of HCC.

AFM tip hammering nanolithography.

Nanolithography at low cost and high speed is made possible by using a vibrating AFM tip in tapping-mode as a nanohammer to forge polystyrene-block-poly(ethylene/butylenes)-block-polystyrene triblock copolymer monolayer thin films after annealing to transform their microstructures from as-cast poorly ordered cylinders into well-ordered hexagonal spheres. Annealing is accomplished in cyclohexane vapor, a selective solvent for the majority poly(ethylene/butylenes) block. Experimental results demonstrate that such structure-tailored thin films enable macroscopic AFM tip writing to be performed in their surface; imprinted and embossed patterns can be generated with a sub-20-nm line-width resolution. In addition, it is found that the lithographic patterns generated can be erased within 5 min by thermal annealing at 70 degrees C, and if necessary the erasion process can be expedited by increasing the annealing temperature.