Sorafenib inhibits tumor growth and improves survival in a transgenic mouse model of pancreatic islet cell tumors

Amygdalin potentiates the anti-cancer effect of Sorafenib on Ehrlich ascites carcinoma and ameliorates the associated liver damage

The burden of cancer diseases is increasing every year, therefore, the demands to figure out novel drugs that can retain antitumor properties have been raised. This study aimed to investigate the anti-tumor properties of amygdalin (Amy) against Ehrlich ascites carcinoma (EAC) bearing mice and its protective properties against liver damage. Amy and the standard anticancer drug Sorafenib (Sor) were given alone or in combination to Swiss albino female mice that had been injected with EAC cells. Biochemical parameters of liver function (AST, ALT, GGT, total protein, albumin), tumor volume, oxidative stress [malondialdehyde, (MDA)] and antioxidative [superoxide dismutase (SOD), and reduced glutathione (GSH)] markers were measured. The hepatic expression of the antioxidant-related gene [nuclear factor erythroid-2-related factor 2 (Nrf2)], the migration-related gene [matrix metalloprotease 9 (MMP9)], and the angiogenesis-related gene [vascular endothelial growth factor (VEGF)] were evaluated by qPCR. The results revealed that EAC-bearing mice treated with Amy and/or Sor showed a decrease in the tumor burden and hepatic damage as evidenced by (1) decreased tumor volume, number of viable tumor cells; (2) increased number of dead tumor cells; (3) restored the liver function parameters; (4) reduced hepatic MDA levels; (5) enhanced hepatic GSH and SOD levels; (6) upregulated expression of Nrf2; (7) downregulated expression of MMP9 and VEGF, and (8) improved hepatic structure. Among all treatments, mice co-treated with Amy (orally) and Sor (intraperitoneally) showed the best effect. With these results, we concluded that the Amy improved the antitumor effect of Sor and had a protective role on liver damage induced by EAC in mice.

The effects of Sorafenib and Natural killer cell co-injection in combinational treatment of hepatocellular carcinoma; an in vivo approach

BACKGROUND

Natural killer cells (NKC) and Sorafenib (Sor) are two important agents for the treatment of hepatocellular carcinoma (HCC). Over the past decade, the interaction of Sor and NKC against HCC has been widely challenging. This study aimed to assess the efficacy of NKC & Sor for the treatment of HCC in vivo.

METHODS

Subcutaneous xenograft models of HCC were established in nude mice. For safety assessment of treatment, the kidney and liver functions were analyzed. Paraffin embedded tumor sections were histopathologically studied and immunohistochemistry (IHC) tests were done to evaluate the angiogenesis (CD34) and proliferation (Ki67) indexes. The terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to identify the tumor cells undergoing apoptosis. The serum levels of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) were measured by enzyme-linked immunosorbent assay (ELISA) and expression levels of major inflammatory cytokines and cytoplasmic granules in xenograft HCC were quantified using real-time PCR.

RESULTS

NKC & Sor significantly inhibited necrosis and apoptosis in tumor cells and increased angiogenesis and proliferation of HCC compared to the monotherapy of NKC or Sor alone. The serum levels of TNF-α, IFN-γ as well as the expression levels of TNF-α, IFN-γ, interleukins (ILs)-1, 6, 10, granzyme-B and perforin in the xenograft HCC tissues of the treated mice with NKC & Sor were significantly lower than those of treated with NKC or Sor alone.

CONCLUSION

Therapy with the specific dosage of NKC & Sor could not inhibit the HCC xenograft growth rate through a synergistic effect in a mouse model of HCC.

Pericytes Elicit Resistance to Vemurafenib and Sorafenib Therapy in Thyroid Carcinoma via the TSP-1/TGFβ1 Axis

PURPOSE

The BRAF^V600E oncogene modulates the papillary thyroid carcinoma (PTC) microenvironment, in which pericytes are critical regulators of tyrosine-kinase (TK)-dependent signaling pathways. Although BRAF^V600E and TK inhibitors are available, their efficacy as bimodal therapeutic agents in BRAF^V600E-PTC is still unknown.

EXPERIMENTAL DESIGN

We assessed the effects of vemurafenib (BRAF^V600E inhibitor) and sorafenib (TKI) as single agents or in combination in BRAF^WT/V600E-PTC and BRAF^WT/WT cells using cell-autonomous, pericyte coculture, and an orthotopic mouse model. We also used BRAF^WT/V600E-PTC and BRAF^WT/WT-PTC clinical samples to identify differentially expressed genes fundamental to tumor microenvironment.

RESULTS

Combined therapy blocks tumor cell proliferation, increases cell death, and decreases motility via BRAF^V600E inhibition in thyroid tumor cells in vitro. Vemurafenib produces cytostatic effects in orthotopic tumors, whereas combined therapy (likely reflecting sorafenib activity) generates biological fluctuations with tumor inhibition alternating with tumor growth. We demonstrate that pericytes secrete TSP-1 and TGFβ1, and induce the rebound of pERK1/2, pAKT and pSMAD3 levels to overcome the inhibitory effects of the targeted therapy in PTC cells. This leads to increased BRAF^V600E-PTC cell survival and cell death refractoriness. We find that BRAF^WT/V600E-PTC clinical samples are enriched in pericytes, and TSP1 and TGFβ1 expression evoke gene-regulatory networks and pathways (TGFβ signaling, metastasis, tumor growth, tumor microenvironment/ECM remodeling functions, inflammation, VEGF ligand-VEGF receptor interactions, immune modulation, etc.) in the microenvironment essential for BRAF^WT/V600E-PTC cell survival. Critically, antagonism of the TSP-1/TGFβ1 axis reduces tumor cell growth and overcomes drug resistance.

CONCLUSIONS

Pericytes shield BRAF^V600E-PTC cells from targeted therapy via TSP-1 and TGFβ1, suggesting this axis as a new therapeutic target for overcoming resistance to BRAF^V600E and TK inhibitors.

Combination therapy of rabies-infected mice with inhibitors of pro-inflammatory host response, antiviral compounds and human rabies immunoglobulin

Recent studies demonstrated that inhibitors of pro-inflammatory molecular cascades triggered by rabies infection in the central nervous system (CNS) can enhance survival in mouse model and that certain antiviral compounds interfere with rabies virus replication in vitro. In this study different combinations of therapeutics were tested to evaluate their effect on survival in rabies-infected mice, as well as on viral load in the CNS. C57Bl/6 mice were infected with Silver-haired bat rabies virus (SHBRV)-18 at virus dose approaching LD₅₀ and LD₁₀₀. In one experimental group daily treatments were initiated 4 h before-, in other groups 48 or 96 h after challenge. In the first experiment therapeutic combination contained inhibitors of tumour necrosis factor-α (infliximab), caspase-1 (Ac-YVAD-cmk), and a multikinase inhibitor (sorafenib). In the treated groups there was a notable but not significant increase of survival compared to the virus infected, non-treated mice. The addition of human rabies immunoglobulins (HRIG) to the combination in the second experiment almost completely prevented mortality in the pre-exposure treatment group along with a significant reduction of viral titres in the CNS. Post-exposure treatments also greatly improved survival rates. As part of the combination with immunomodulatory compounds, HRIG had a higher impact on survival than alone. In the third experiment the combination was further supplemented with type-I interferons, ribavirin and favipiravir (T-705). As a blood-brain barrier opener, mannitol was also administered. This treatment was unable to prevent lethal consequences of SHBRV-18 infection; furthermore, it caused toxicity in treated mice, presumably due to interaction among the components. In all experiments, viral loads in the CNS were similar in mice that succumbed to rabies regardless of treatment. According to the findings, inhibitors of detrimental host response to rabies combined with antibodies can be considered among the possible therapeutic and post-exposure options in human rabies cases.

Comprehensive establishment and characterization of orthoxenograft mouse models of malignant peripheral nerve sheath tumors for personalized medicine

Malignant peripheral nerve sheath tumors (MPNSTs) are soft-tissue sarcomas that can arise either sporadically or in association with neurofibromatosis type 1 (NF1). These aggressive malignancies confer poor survival, with no effective therapy available. We present the generation and characterization of five distinct MPNST orthoxenograft models for preclinical testing and personalized medicine. Four of the models are patient-derived tumor xenografts (PDTX), two independent MPNSTs from the same NF1 patient and two from different sporadic patients. The fifth model is an orthoxenograft derived from an NF1-related MPNST cell line. All MPNST orthoxenografts were generated by tumor implantation, or cell line injection, next to the sciatic nerve of nude mice, and were perpetuated by 7–10 mouse-to-mouse passages. The models reliably recapitulate the histopathological properties of their parental primary tumors. They also mimic distal dissemination properties in mice. Human stroma was rapidly lost after MPNST engraftment and replaced by murine stroma, which facilitated genomic tumor characterization. Compatible with an origin in a catastrophic event and subsequent genome stabilization, MPNST contained highly altered genomes that remained remarkably stable in orthoxenograft establishment and along passages. Mutational frequency and type of somatic point mutations were highly variable among the different MPNSTs modeled, but very consistent when comparing primary tumors with matched orthoxenografts generated. Unsupervised cluster analysis and principal component analysis (PCA) using an MPNST expression signature of ~1,000 genes grouped together all primary tumor–orthoxenograft pairs. Our work points to differences in the engraftment process of primary tumors compared with the engraftment of established cell lines. Following standardization and extensive characterization and validation, the orthoxenograft models were used for initial preclinical drug testing. Sorafenib (a BRAF inhibitor), in combination with doxorubicin or rapamycin, was found to be the most effective treatment for reducing MPNST growth. The development of genomically well-characterized preclinical models for MPNST allowed the evaluation of novel therapeutic strategies for personalized medicine.

Inhibition of heat shock protein 90 with AUY922 represses tumor growth in a transgenic mouse model of islet cell neoplasms

BACKGROUND

This study was designed to evaluate the role of heat shock protein 90 (HSP90) in tumor progression of murine islet cell tumors. Blockade of HSP90 has recently been proposed as a therapeutic target, but effects in models of islet cell tumors with AUY922, a newly developed HSP90 inhibitor, have not been examined.

MATERIAL AND METHODS

The carcinoid cell line BON-1 and the HSP90 inhibitor AUY922 were used to determine effects on signaling and growth in vitro. In vivo transgenic RIP1-Tag2 mice, which develop islet cell neoplasms, were treated with vehicle or AUY922 (25 mg/kg/twice per week) from week 5 until death. The resected pancreata were evaluated macroscopically and microscopically by immunohistochemistry. Quantitative real-time PCR was performed for HSP90 targets with RNA from islets isolated from treated and untreated RIP1-Tag2 mice.

RESULTS

HSP90 blockade impaired constitutive and growth factor-induced signaling in vitro. Moreover, HSP90 inhibition attenuated in vitro cell growth in a dose-dependent manner. In vivo, AUY922 significantly reduced tumor volume by 92% compared to untreated controls (p = 0.000), and median survival in the used transgenic mouse model was prolonged (110 vs. 119 days; p = 0.75). Quantitative real-time PCR for downstream target genes of HSP90 demonstrated significant downregulation in the islet cell tumors of RIP1-Tag2 mice treated with AUY922, confirming our ability to achieve effective pharmacologic levels of AUY922 within the desired tissue site in vivo.

CONCLUSION

This is the first study to show that the HSP90 antagonist AUY922 may provide a new option for therapy of islet cell neoplasms.