Efficacy and toxicity of molecular targeted therapies in combination with docetaxel for metastatic castration-resistant prostate cancer: a meta-analysis of phase III randomized controlled trials

Heterotargeted Nanococktail with Traceless Linkers for Eradicating Cancer

Clinical application of drug cocktails for cancer therapy is limited by their severe systemic toxicity. To solve a catch-22 dilemma between safety and efficacy for drug cocktails, a hetero-targeted nano-cocktail (PPPDMA) with traceless linkers has been developed. In the PPPDMA nanogel, a hetero-targeting strategy is employed to improve its tumor selective targeting efficacy by overcoming the cancer cell mono-ligand density limitation. Benefit from its glutathione and reactive oxygen species responsiveness, the loaded paclitaxel and doxorubicin can be quickly and tracelessly released into the cytoplasm in their original form, which bestows PPPDMA nanogels the capability to overwhelm the processing capacity of cancer cell's P-glycoprotein efflux pump allows, and ultimately kill them without inducing side effects. The PPPDMA treatment reduced its tumor burden over 99% (in tumor weight) and 96% (in tumor number). Most importantly, no detectable tumor in more than half of the PPPDMA treated mice. We conclude that traceless linker and hetero-targeted nano-cocktail strategy could be a safe and effective approach for cancer treatment.

Prostate cancer cells hyper-activate CXCR6 signaling by cleaving CXCL16 to overcome effect of docetaxel

Molecular reprogramming in response to chemotherapeutics leads to poor therapeutic outcomes for prostate cancer (PCa). In this study, we demonstrated that CXCR6-CXCL16 axis promotes DTX resistance and acts as a counter-defense mechanism. After CXCR6 activation, cell death in response to DTX was inhibited, and blocking of CXCR6 potentiated DTX cytotoxicity. Moreover, in response to DTX, PCa cells expressed higher CXCR6, CXCL16, and ADAM-10. Furthermore, ADAM-10-mediated release of CXCL16 hyper-activated CXCR6 signaling in response to DTX. Activation of CXCR6 resulted in increased GSK-3β, NF-κB, ERK1/2 phosphorylation, and survivin expression, which reduce DTX response. Finally, treatment of PCa cells with anti-CXCR6 monoclonal antibody synergistically or additively induced cell death with ∼1.5-4.5 fold reduction in the effective concentration of DTX. In sum, our data imply that co-targeting of CXCR6 would lead to therapeutic enhancement of DTX, leading to better clinical outcomes for PCa patients.

Effectiveness and tolerability of targeted drugs for the treatment of metastatic castration-resistant prostate cancer: a network meta-analysis of randomized controlled trials

PURPOSE

Castration-resistant prostate cancer (CRPC) refers to prostate cancer that has progressed after initial androgen deprivation therapy (ADT). Over the years, treatment strategies for metastatic CRPC (mCRPC) have undergone considerable changes. We performed a network meta-analysis to assess the effectiveness and tolerability of targeted agents for mCRPC.

METHODS

We search databases including MEDLINE, EMBASE, and the Cochrane Library through Sep 5, 2017. The major effectiveness outcomes were progression-free survival (PFS) and overall survival (OS). The tolerability outcome was severe adverse events (AEs) of grade ≥ 3.

RESULTS

Twenty-six articles assessing a total of 20,314 patients were included in this study. A random-effect analysis showed that targeted agents could significant prolong PFS in mCRPC patients (I² = 94.3%; hazard ratio (HR): 0.74; 95% confidence interval (CI): 0.65-0.84; p < 0.001). In addition, the surface under the cumulative ranking curve (SUCRA) ranking from the network analysis showed that enzalutamide was the most effective in improving the PFS of mCRPC patients (100%), followed by abiraterone (90.1%) and tasquinimod (84.2%). Additionally, targeted agents could clearly prolong OS in mCRPC patients (I² = 71.6%; HR: 0.91; 95% CI: 0.85-0.97; p < 0.001). Furthermore, based on SUCRA ranking, enzalutamide was the most effective in improving the OS of mCRPC patients (97.2%), followed by abiraterone (91.1%) and zibotentan (65.8%). Intetumumab was associated with the lowest incidence of severe AEs (94.9%), followed by atrasentan (85.1%) and placebo (79.3%).

CONCLUSION

In patients with mCRPC, enzalutamide, abiraterone and tasquinimod can prolong PFS, and enzalutamide and abiraterone can prolong OS. Additionally, enzalutamide and abiraterone can improve both PFS and OS with a low risk of causing severe AEs.

ATM‑JAK‑PD‑L1 signaling pathway inhibition decreases EMT and metastasis of androgen‑independent prostate cancer

Castration-resistant prostate cancer (CRPC), also known as androgen-independent prostate cancer, frequently develops local and distant metastases, the underlying mechanisms of which remain undetermined. In the present study, surgical specimens obtained from patients with clinical prostate cancer were investigated, and it was revealed that the expression levels of ataxia telangiectasia mutated kinase (ATM) were significantly enhanced in prostate cancer tissues isolated from patients with CRPC compared with from patients with hormone-dependent prostate cancer. CRPC C4-2 and CWR22Rv1 cells lines were subsequently selected to establish prostate cancer models, and ATM knockout cells were established via lentivirus infection. The results of the present study demonstrated that the migration and epithelial-mesenchymal transition (EMT) of ATM knockout cells were significantly decreased, which suggested that ATM is closely associated with CRPC cell migration and EMT. To further investigate the mechanisms underlying this process, programmed cell death 1 ligand 1 (PD-L1) expression was investigated in ATM knockout cells. In addition, inhibitors of Janus kinase (JAK) and signal transducer and activator of transcription 3 (STAT3; Stattic) were added to C4-2-Sc and CWR22Rv1-Sc cells, and the results demonstrated that PD-L1 expression was significantly decreased following the addition of JAK inhibitor 1; however, no significant change was observed following the addition of Stattic. Furthermore, a PD-L1 antibody and JAK inhibitor 1 were added to C4-2-Sc and CWR22Rv1-Sc cells, and it was revealed that cell migration ability was significantly decreased and the expression of EMT-associated markers was effectively reversed. The results of the present study suggested that via inhibition of the ATM-JAK-PD-L1 signaling pathway, EMT, metastasis and progression of CRPC may be effectively suppressed, which may represent a novel therapeutic approach for targeted therapy for patients with CRPC.

Treatment with docetaxel in combination with Aneustat leads to potent inhibition of metastasis in a patient-derived xenograft model of advanced prostate cancer

Background:

Docetaxel used for first-line treatment of advanced prostate cancer (PCa) is only marginally effective. We previously showed, using the LTL-313H subrenal capsule patient-derived metastatic PCa xenograft model, that docetaxel combined with Aneustat (OMN54), a multivalent plant-derived therapeutic, led to marked synergistic tumour growth inhibition. Here, we investigated the effect of docetaxel+Aneustat on metastasis.

Methods:

C4-2 cells were incubated with docetaxel, Aneustat and docetaxel+Aneustat to assess effects on cell migration. The LTL-313H model, similarly treated, was analysed for effects on lung micro-metastasis and kidney invasion. The LTL-313H gene expression profile was compared with profiles of PCa patients (obtained from Oncomine) and subjected to IPA to determine involvement of cancer driver genes.

Results:

Docetaxel+Aneustat markedly inhibited C4-2 cell migration and LTL-313H lung micro-metastasis/kidney invasion. Oncomine analysis indicated that treatment with docetaxel+Aneustat was associated with improved patient outcome. The drug combination markedly downregulated expression of cancer driver genes such as FOXM1 (and FOXM1-target genes). FOXM1 overexpression reduced the anti-metastatic activity of docetaxel+Aneustat.

Conclusions:

Docetaxel+Aneustat can inhibit PCa tissue invasion and metastasis. This activity appears to be based on reduced expression of cancer driver genes such as FOXM1. Use of docetaxel+Aneustat may provide a new, more effective regimen for therapy of metastatic PCa.