Combination therapy with carboplatin and thalidomide suppresses tumor growth and metastasis in 4T1 murine breast cancer model

Current views on in vivo models for breast cancer research and related drug development

INTRODUCTION

Animal models play a crucial role in breast cancer research, in particular mice and rats, who develop mammary tumors that closely resemble their human counterparts. These models allow the study of mechanisms behind breast carcinogenesis, as well as the efficacy and safety of new, and potentially more effective and advantageous therapeutic approaches. Understanding the advantages and disadvantages of each model is crucial to select the most appropriate one for the research purpose.

AREA COVERED

This review provides a concise overview of the animal models available for breast cancer research, discussing the advantages and disadvantages of each one for searching new and more effective approaches to treatments for this type of cancer.

EXPERT OPINION

Rodent models provide valuable information on the genetic alterations of the disease, the tumor microenvironment, and allow the evaluation of the efficacy of chemotherapeutic agents. However, in vivo models have limitations, and one of them is the fact that they do not fully mimic human diseases. Choosing the most suitable model for the study purpose is crucial for the development of new therapeutic agents that provide better care for breast cancer patients.

Potential Use of Thalidomide in Glioblastoma Treatment: An Updated Brief Overview

Glioblastoma is the most common malignant primary brain tumor in adults. Thalidomide is a vascular endothelial growth factor inhibitor that demonstrates antiangiogenic activity, and may provide additive or synergistic anti-tumor effects when co-administered with other antiangiogenic medications. This study is a comprehensive review that highlights the potential benefits of using thalidomide, in combination with other medications, to treat glioblastoma and its associated inflammatory conditions. Additionally, the review examines the mechanism of action of thalidomide in different types of tumors, which may be beneficial in treating glioblastoma. To our knowledge, a similar study has not been conducted. We found that thalidomide, when used in combination with other medications, has been shown to produce better outcomes in several conditions or symptoms, such as myelodysplastic syndromes, multiple myeloma, Crohn's disease, colorectal cancer, renal failure carcinoma, breast cancer, glioblastoma, and hepatocellular carcinoma. However, challenges may persist for newly diagnosed or previously treated patients, with moderate side effects being reported, particularly with the various mechanisms of action observed for thalidomide. Therefore, thalidomide, used alone, may not receive significant attention for use in treating glioblastoma in the future. Conducting further research by replicating current studies that show improved outcomes when thalidomide is combined with other medications, using larger sample sizes, different demographic groups and ethnicities, and implementing enhanced therapeutic protocol management, may benefit these patients. A meta-analysis of the combinations of thalidomide with other medications in treating glioblastoma is also needed to investigate its potential benefits further.

Complex Effects of Sertraline and Citalopram on In Vitro Murine Breast Cancer Proliferation and on In Vivo Progression and Anxiety Level

Some selective serotonin reuptake inhibitors (SSRIs), primarily sertraline, demonstrate anti-proliferative activity in malignant cell-lines and in xenografted mouse models of colorectal tumor. There is, however, a paucity of comparative studies on the anti-tumor effects of SSRIs. We compared the in vitro and in vivo effects of sertraline and citalopram on murine 4T1 breast cancer. Grafted mice were used to determine the rate of tumor growth and survival as well as the impact of stress and antidepressant treatment on tumor progression and mortality and on pro-inflammatory cytokines. Sertraline, in the micromolar range, but not citalopram, induced a significant in vitro concentration-dependent inhibition of murine 4T1 cell proliferation and splenocyte viability. In contrast, sertraline (10 mg/kg/d), enhanced in vivo tumor growth. Contrary to the study's hypothesis, chronic mild stress did not modify tumor growth in grafted mice. The in vitro effects of sertraline on tumor growth seem to be the opposite of its in vivo effects. The impact of sertraline treatment on humans with breast cancer should be further investigated.

Anti-Angiogenic Therapy: Current Challenges and Future Perspectives

Anti-angiogenic therapy is an old method to fight cancer that aims to abolish the nutrient and oxygen supply to the tumor cells through the decrease of the vascular network and the avoidance of new blood vessels formation. Most of the anti-angiogenic agents approved for cancer treatment rely on targeting vascular endothelial growth factor (VEGF) actions, as VEGF signaling is considered the main angiogenesis promotor. In addition to the control of angiogenesis, these drugs can potentiate immune therapy as VEGF also exhibits immunosuppressive functions. Despite the mechanistic rational that strongly supports the benefit of drugs to stop cancer progression, they revealed to be insufficient in most cases. We hypothesize that the rehabilitation of old drugs that interfere with mechanisms of angiogenesis related to tumor microenvironment might represent a promising strategy. In this review, we deepened research on the molecular mechanisms underlying anti-angiogenic strategies and their failure and went further into the alternative mechanisms that impact angiogenesis. We concluded that the combinatory targeting of alternative effectors of angiogenic pathways might be a putative solution for anti-angiogenic therapies.

The Assessment of the Combined Treatment of 5-ALA Mediated Photodynamic Therapy and Thalidomide on 4T1 Breast Carcinoma and 2H11 Endothelial Cell Line

Photodynamic therapy (PDT) is a low-invasive method of treatment of various diseases, mainly neoplastic conditions. PDT has been experimentally combined with multiple treatment methods. In this study, we tested a combination of 5-aminolevulinic acid (5-ALA) mediated PDT with thalidomide (TMD), which is a drug presently used in the treatment of plasma cell myeloma. TMD and PDT share similar modes of action in neoplastic conditions. Using 4T1 murine breast carcinoma and 2H11 murine endothelial cells lines as an experimental tumor model, we tested 5-ALA-PDT and TMD combination in terms of cytotoxicity, apoptosis, Vascular Endothelial Growth Factor (VEGF) expression, and, in 2H11 cells, migration capabilities by wound healing assay. We have found an enhancement of cytotoxicity in 4T1 cells, whereas, in normal 2H11 cells, this effect was not statistically significant. The addition of TMD decreased the production of VEGF after PDT in 2H11 cell line. Our results reveal enhanced effectiveness of 5-ALA-PDT with TMD treatment compared to 5-ALA-PDT or TMD treatment alone. The addition of TMD may be a promising proceeding of the anti-tumor effect of PDT by decreasing the VEGF concentration in the culture medium. Further studies, including testing on different cell lines, are needed to confirm this assumption.

Encapsulating paclitaxel in polymeric nanomicelles increases antitumor activity and prevents peripheral neuropathy

Paclitaxel (PTX) has a great clinical significance as an antitumor drug, although several side effects are strongly dose-limiting. In this way, we prepared a PTX-loaded 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol)-2000] polymeric micelles (PM/PTX) in an attempt to improve safety and effectiveness of conventional PTX formulation (CrEL/EtOH/PTX). In this study, we evaluated from both formulations: stability after dilution, hemocompatibility, cellular uptake, acute toxicity in healthy mice, antitumor activity, and toxicity after multiple-dose treatment. PM/PTX appeared to be more stable than CrEL/EtOH/PTX after dilution. PM/PTX did not exhibit hemolytic activity (values <1%), even at high concentrations. In vitro cellular uptake study indicated that polymeric micelles were able to deliver more PTX (5.8 %) than CrEL/EtOH (2.7 %) to 4T1 cells. In the acute toxicity evaluation in healthy mice, CrEL/EtOH/PTX (single dose of 20 mg/kg) induced peripheral neuropathy, which was not observed in PM/PTX group. Similar results were observed after tumor-bearing mice received a multiple-dose regimen (seven doses of 10 mg/kg). Worth mentioning, we also evaluated vehicles, and CrEL/EtOH alone was not capable of inducing neuropathic pain. Besides, PM/PTX exhibited a higher antitumor activity with an inhibition ratio approximately 1.5-fold higher than CrEL/EtOH/PTX group. This study suggested that PM/PTX is safer than CrEL/EtOH/PTX, and was able to improve the antitumor effectiveness in a 4T1 breast cancer model.

Delivery and Effectiveness of Carboplatin via Targeted Delivery Compared to Passive Accumulation of Intravenously Injected Particles Releasing Carboplatin upon Irradiation

In this study, nanoparticles that release anticancer drugs upon irradiation were developed. Here, MM46 and MM48 tumors in C3He/N mice were irradiated. Furthermore, the intravenously (i.v.) injected nanoparticles were tested for their ability to deliver the anticancer drug, increase the antitumor effect via a synergistic effect of combining targeted anticancer drugs with radiation and decrease adverse effects by localizing the anticancer drug. The nanoparticles were prepared by spraying a mixture of hyaluronic acid and alginate, supplemented with carboplatin, into a solution of CaCl₂ and FeCl₂ through a 0.8-lm-pore stainless mesh filter. Nanoparticles (1 × 10¹⁰) were i.v. injected and irradiated (100-KeV soft X rays, 10-40 Gy) when the accumulation of particles peaked. The nanoparticles were 547 ± 43 nm in diameter. The i.v.-injected nanoparticles accumulated around tumors. Maximum accumulations were observed 9 h post-injection. Subsequently, 10-40 Gy of radiation was administered. The accumulated nanoparticles released the carboplatin and gelatinized their outer shells, which prolonged the intra-tumor concentration of carboplatin and increased the radiation-induced synergistic antitumor effect. The localization of carboplatin by nanoparticles significantly reduced the adverse effects of the anticancer drug.

Tumor vasculature remolding by thalidomide increases delivery and efficacy of cisplatin

Background

A promising strategy to overcome the chemoresistance is the tumor blood vessel normalization, which restores the physiological perfusion and oxygenation of tumor vasculature. Thalidomide (Thal) has been shown to increase the anti-tumor effect of chemotherapy agents in solid tumors. However, it is not yet known whether the synergistic effect of Thal combined with other cytotoxic drugs is attributable to tumor vascular normalization.

Methods

We used two homograft mice models (4 T1 breast tumor model and CT26 colorectal tumor model) to investigate the effect of Thal on tumor growth, microvessel density, vascular physiology, vascular maturity and function, drug delivery and chemosensitivity. Immunofluorescence, immunohistochemistry and scanning electron microscopy were performed to determine the vessel changes. Protein array assay, qPCR and western blotting were used to detect the molecular mechanism by which Thal regulates tumor vascular.

Results

Here we report that Thal potently suppressed tumor growth, angiogenesis, hypoxia, and vascular permeability in animal models. Thal also induced a regular monolayer of endothelial cells in tumor vessels, inhibiting vascular instability, and normalized tumor vessels by increasing vascular maturity, pericyte coverage and endothelial junctions. The tumor vessel stabilization effect of Thal resulted in a decrease in tumor vessel tortuosity and leakage, and increased vessel thickness and tumor perfusion. Eventually, the delivery of cisplatin was highly enhanced through the normalized tumor vasculature, thus resulting in profound anti-tumor and anti-metastatic effects. Mechanistically, the effects of Thal on tumor vessels were caused in part by its capability to correct the imbalance between pro-angiogenic factors and anti-angiogenic factors.

Conclusions

Our findings provide direct evidence that Thal remodels the abnormal tumor vessel system into a normalized vasculature. Our results may lay solid foundation for the development of Thal as a novel candidate agent to maximize the therapeutic efficacy of chemotherapeutic drugs for solid tumors.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1366-x) contains supplementary material, which is available to authorized users.

Scandenolone from Cudrania tricuspidata fruit extract suppresses the viability of breast cancer cells (MCF-7) in vitro and in vivo

Scandenolone, an isoflavone, has shown anti-cancer potential. In this study, we extracted scandenolone from Cudrania tricuspidata fruit and evaluated its anti-breast cancer effects as well as toxicity in cell and animal models. In cell model, scandenolone suppressed the breast cancer MCF-7 cells viability, ceased mitotic cell cycle, decreased mitochondrial membrane potential, up-regulated cleaved caspase-3 and promoted the phosphorylation of p53. Additionally, this isoflavone promoted cell apoptosis and induced a sustained activation of the phosphorylation of p38 and ERK, but not JNK and Akt. The effects were further verified in a human MCF-7 breast cancer xenograft model, where scandenolone efficiently suppressed the cancer growth and increased apoptotic cells in tumor tissue. However scandenolone has also shown certain toxicity to normal hepatocytes and breast epithelial cells. It could be concluded that scandenolone suppressed the growth of breast cancer cells, but its toxicity towards normal cells might limit its potential clinical use.

Comparison of [18F]Fluorocholine and [18F]Fluordesoxyglucose for assessment of progression, lung metastasis detection and therapy response in murine 4T1 breast tumor model

The [18F]Fluorocholine ([18F]FCH) tracer for PET imaging has been proven to be effective for several malignances. However, there are only a few studies related to its breast tumor applicability and they are still limited. The aim of this study was investigate the efficacy of [18F]FCH/PET compared to [18F]FDG/PET in a murine 4T1 mammary carcinoma model treated and nontreated. [18F]FCH/PET showed its applicability for primary tumor and lung metastasis detection and their use for response monitoring of breast cancer therapeutics at earlier stages.

Thalidomide potentiates etoposide-induced apoptosis in murine neuroblastoma through suppression of NF-κB activation

PURPOSE

Treatment for high-risk neuroblastoma is still challenging. The purpose of the present study was to determine whether thalidomide suppresses etoposide-induced NF-κB activation and thus potentiates apoptosis in murine neuroblastoma.

METHODS

A murine neuroblastoma cell line, C1300, and A/J mice were used in this study. We evaluated NF-κB activation after using etoposide with or without thalidomide by quantitative analysis of NF-κB by ELISA and by Western blot analysis of IκB phosphorylation in vitro and in vivo. Induction of apoptosis was evaluated by Western blot analysis of the apoptotic signals caspase-3, 8, and 9 in vitro and by TUNEL assays in vivo. We also evaluated the efficacy of the combination of etoposide and thalidomide by assessing tumor growth and mouse survival in vivo.

RESULTS

Etoposide activated NF-κB in C1300 cells. This activation was suppressed by thalidomide and IκB was re-upregulated. The apoptotic signals were enhanced by the combination of thalidomide and etoposide compared with etoposide alone in vitro, which was consistent with TUNEL assays. The combination of etoposide and thalidomide also slowed tumor growth and mouse survival.

CONCLUSION

Thalidomide potentiates etoposide-induced apoptosis in murine neuroblastoma by suppressing NF-κB.

Vascular endothelial growth receptor 1 acts as a stress-associated protein in the therapeutic response to thalidomide

Thalidomide (THD) exhibits antitumor effects in several types of cancer. However, the failure of THD to inhibit tumor growth has also been observed in a number of murine models in vivo. The mechanism involved in the therapeutic failure of THD remains unclear. The present study demonstrated that, accompanied by growth-arresting and apoptosis-inducing effects (P<0.05), THD upregulated vascular endothelial growth factor receptor 1 (VEGFR1) expression levels in CT26 murine colorectal carcinoma cell lines. This in vitro phenomenon was also observed in various other cell lines, including human umbilical vein endothelial cells, SW480, SW620 and HCT116. Reactive oxygen species (ROS) levels were increased compared with those in the untreated control when cells were exposed to THD (P<0.05). Furthermore, results suggested that ROS suppression may have provoked the induction of VEGFR1 expression to some extent. In addition, the results revealed that THD failed to inhibit CT26 tumor growth in vivo and the expression of VEGFR1 protein was elevated by THD treatment compared with the control group in the murine colorectal tumor model (P<0.05). The results of further experiments suggested that VEGFR1 was elevated in response to various stress-associated situations, including chemotherapy, radiotherapy and thermotherapy, which indicate that it may act as a stress-associated protein. The present findings provide a foundation for the future study of VEGFR1-targeted therapy to enhance the efficacy of current therapies.

Synthesis and evaluation of 5-(arylthio)-9H-pyrimido[4,5-b]indole-2,4-diamines as receptor tyrosine kinase and thymidylate synthase inhibitors and as antitumor agents

In an effort to optimize the structural requirements for combined cytostatic and cytotoxic effects in single agents, a series of 5-(arylthio)-9H-pyrimido[4,5-b]indole-2,4-diamines 3-7 were synthesized and evaluated as inhibitors of receptor tyrosine kinases (RTKs) as well as thymidylate synthase (TS). The synthesis of these compounds involved the nucleophilic displacement of the common intermediate 5-bromo/5-chloro-9H-pyrimido[4,5-b]indole-2,4-diamine with appropriate aryl thiols. A novel four step synthetic scheme to the common intermediate was developed which is more efficient relative to the previously reported six-step sequence. Biological evaluation of these compounds indicated dual activity in RTKs and human TS (hTS). In the VEGFR-2 assay, compound 5 was equipotent to the standard compound semaxanib and was better than standard TS inhibitor pemetrexed, in the hTS assay. Compounds 3, 6 and 7 were nanomolar inhibitors of hTS and were several fold better than pemetrexed.

Anticancer effect of thalidomide in vitro on human osteosarcoma cells

Osteosarcoma is a high‑grade malignant tumor frequently found in children and adolescents. Thalidomide has been reported for treatment of various malignancies. Thalidomide was added to osteosarcoma cells and studied by cytotoxicity assay, evaluating apoptosis, cell cycle arrest, mitochondrial membrane potential (ΔΨm), and reactive oxygen species (ROS) levels and the expression of Bcl‑2, Bax, caspase‑3 and NF‑κB. The results showed that thalidomide could inhibit the proliferation of MG‑63 and U2OS cells in a concentration‑ and time‑dependent manner. Morphological changes of apoptosis were also observed. Thalidomide increased the apoptosis rate of MG‑63 cells and induced cell cycle arrest by increasing the number of cells in the G0/G1 phase and decreasing the percentage of S phase in MG‑63 cells. Further investigation showed that a disruption of ΔΨm and upregulation of ROS were induced by thalidomide in high concentration. By western blot analysis, thalidomide resulted in the decreasing expression of Bcl‑2 and NF‑κB, and the increasing expression of Bcl‑2/Bax and caspase‑3. Here, we provide evidence that thalidomide could cause apoptosis in osteosarcoma cells. Taken together, these results indicate that thalidomide could be an antitumor drug in the therapy of osteosarcoma.

Chitosan-based nanoparticles for survivin targeted siRNA delivery in breast tumor therapy and preventing its metastasis

Nanoparticle-mediated small interfering RNA (siRNA) delivery is a promising therapeutic strategy in various cancers. However, it is difficult to deliver degradative siRNA to tumor tissue, and thus a safe and efficient vector for siRNA delivery is essential for cancer therapy. In this study, poly(ethylene glycol)-modified chitosan (PEG-CS) was synthesized successfully for delivering nucleic acid drug. We deemed that PEGylated CS could improve its solubility by forming a stable siRNA loaded in nanoparticles, and enhancing transfection efficiency of siRNA-loaded CS nanoparticles in cancer cell line. The research results showed that siRNA loaded in PEGylated CS (PEG-CS/siRNA) nanoparticles with smaller particle size had superior structural stability in the physical environment compared to CS nanoparticles. The data of in vitro antitumor activity revealed that 4T1 tumor cell growth was significantly inhibited and cellular uptake of PEG-CS/siRNA nanoparticles in 4T1 cells was dramatically enhanced compared to naked siRNA groups. The results from flow cytometry and confocal laser scanning microscopy showed that PEG-CS/siRNA nanoparticles were more easily taken up than naked siRNA. Importantly, PEG-CS/siRNA nanoparticles significantly reduced the growth of xenograft tumors of 4T1 cells in vivo. It has been demonstrated that the PEG-CS is a safe and efficient vector for siRNA delivery, and it can effectively reduce tumor growth and prevent metastasis.

Absence of significant adverse events following thalidomide administration in bitches diagnosed with mammary gland carcinomas

The aim of the study was to evaluate the incidence of adverse events (AEs) in female dogs diagnosed with advanced clinical stage mammary gland neoplasms following treatment with thalidomide. A prospective analysis of 29 female dogs treated with a high dose (HD) of 20 mg/kg/day of thalidomide for three months followed by a low dose (LD) of 10 mg/kg/day of thalidomide for three months was performed. All patients underwent physical examination, complete blood count, serum biochemistry profile, thoracic radiographs, and abdominal ultrasound analysis before the treatment and after the HD and LD. Clinical AEs were absent in 16/29 (55.17 per cent) patients following HD. An initial 3-5 day period of somnolence was described in 4/29 (13.79 per cent), prolonged somnolence in 5/29 (17.24 per cent), a short period of somnolence lasting only a few hours in 3/29 (10.34 per cent), and difficulty to rouse was described in 5/29 (17.24 per cent) cases. Two patients (6.89 per cent) presented with prolonged somnolence that interfered with activities of daily living, resulting in anticipation of the dose reduction to the proposed LD after 15 days of the HD treatment. Following dose reduction, AE improvement was observed in all patients. Albeit remaining within the reference ranges, erythrocytes, haematocrit, total leucocyte count, neutrophils, lymphocytes, monocytes and γ-glutamyltranspeptidase showed significant alteration associated to thalidomide treatment.

Effect of thalidomide in combination with gemcitabine on human pancreatic carcinoma SW-1990 cell lines in vitro and in vivo

Pancreatic cancer is one of the most frequently occurring malignancies worldwide and it is the fourth most common cause of cancer-associated mortality in Western countries. Thalidomide (THD) plays an important role in tumor therapy, as it is able to promote early stage apoptosis and inhibit the process of angiogenesis. The present study evaluated the ability of the combination of THD and gemcitabine (GEM) to inhibit the growth of the pancreatic cancer SW-1990 cell line in vitro and in vivo. Early apoptosis in the SW-1990 cells was detected by the Annexin V/propidium iodide double staining method, the level of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) were detected by reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis. In addition, the expression of vascular endothelial growth factor in transplanted tumor tissue was measured by RT-PCR, immunohistochemistry and western blot analysis. Cluster of differentiation 34 positivity was considered to indicate the microvessel density. Subsequent to treatment with THD and GEM alone or in combination, it was found that the expression of Bax was upregulated, while the expression of Bcl-2 was downregulated, and the growth of SW-1990 cells and transplanted tumors in nude mice was evidently inhibited. The administration of THD in combination with GEM may demonstrate a potent antitumor effect that increases with increasing dose. The mechanism behind the antitumor effect may be associated with the inhibition of tumor angiogenesis and induction of the apoptosis pathway.

Linking the future of anticancer metal-complexes to the therapy of tumour metastases

Cancer chemotherapy is almost always applied to patients with one or more diagnosed metastases and is expected to impact these lesions, thus providing significant benefits to the patient.