Effects of thalidomide on angiogenesis and tumor growth and metastasis of human hepatocellular carcinoma in nude mice

2-(Piperidin-3-yl)phthalimides reduce classical markers of cellular inflammation in LPS-challenged RAW 264.7 cells and also demonstrate potentially relevant sigma and serotonin receptor affinity in membrane preparations

Herein, we report the synthesis of new 4-amino-2-(piperidin-3-yl)isoindoline-1,3-diones and their biological evaluation in a series of in vitro experiments. The synthetic production of these materials was initiated upon the condensation of appropriate nitrophthalic acid derivatives with various 3-aminopiperidines; subsequent reduction provided the final products in moderate to good yields. Readily available chiral pool reagents facilitated entry into optically enriched samples, while the piperidine scaffold furnished a variety of amide and alkylated entries. In total, 16 candidates were produced, and their ensuing treatment in LPS-challenged RAW cells effected slight reductions in secreted TNF-α but provided more robust and dose-dependent declines in nitrite and IL-6 levels relative to basal amounts, all concurrent with maintenance of cellular viability across the concentration ranges screened. The secondary amine cohort including rac-6, (R)-7, and (S)-8 rendered the most pronounced dose-dependent reductions in nitrite and IL-6. When dosed at 30 μM, (R)-7 demonstrated the most compelling effects, with decreases of 32 % and 40 % for nitrite and IL-6, respectively. Notable reductions in the inflammatory markers were also observed for 19 which effected declines in TNF-α (14 %), nitrite (19 %), and IL-6 (11 %) when treated at 30 μM. Additionally, four representative compounds were further evaluated against numerous CNS receptors, channels, and transporters, with 6, 9, and 19 demonstrating varying degrees of nanomolar-to-low-micromolar binding to the σ-1 and σ-2 receptors and also to serotonin receptors 5HT2A, 5HT2B and 5HT3. In this regard, 6 displayed perhaps the most noteworthy affinities, with binding at σ-2 (Ki = 2.2uM), 5HT2B (Ki = 561 nM) and 5HT3 (Ki = 536 nM). Furthermore, no pronounced or dose-dependent Cereblon/DDB1 binding was observed for the screened representative compounds 6, 9, 18 and 19.

Metronomic chemotherapy: bridging theory to clinical application in canine and feline oncology

Veterinary oncology has experienced significant evolution over the last few decades, with chemotherapy being currently applied to several neoplasms with therapeutic success. Traditionally, chemotherapy protocols are based on classic cytostatic drugs under the concept of maximum tolerated dose (MTD), which has been associated with a greater risk of toxicity and resistance. Thus, new therapeutic alternatives have emerged, such as metronomic chemotherapy (MC), introducing a new paradigm in cancer treatment. MC consists of administering low doses of chemotherapy drugs continuously over a long period of time, modulating the tumour microenvironment (TME) due to the combination of cytotoxic, antiangiogenic and immunomodulatory effects. This multi-targeted therapy has been described as a treatment option in several canine and feline cancers since 2007, with positive results already published in the literature, particularly in mammary carcinomas and soft tissue sarcomas in dogs. The aim of this review article is to describe the current knowledge about the use of MC in small animal oncology, with emphasis on its mechanisms of action, the most commonly used drugs and clinical outcome.

Repurposing Cardiac Glycosides: Drugs for Heart Failure Surmounting Viruses

Drug repositioning is a successful approach in medicinal research. It significantly simplifies the long-term process of clinical drug evaluation, since the drug being tested has already been approved for another condition. One example of drug repositioning involves cardiac glycosides (CGs), which have, for a long time, been used in heart medicine. Moreover, it has been known for decades that CGs also have great potential in cancer treatment and, thus, many clinical trials now evaluate their anticancer potential. Interestingly, heart failure and cancer are not the only conditions for which CGs could be effectively used. In recent years, the antiviral potential of CGs has been extensively studied, and with the ongoing SARS-CoV-2 pandemic, this interest in CGs has increased even more. Therefore, here, we present CGs as potent and promising antiviral compounds, which can interfere with almost any steps of the viral life cycle, except for the viral attachment to a host cell. In this review article, we summarize the reported data on this hot topic and discuss the mechanisms of antiviral action of CGs, with reference to the particular viral life cycle phase they interfere with.

The use of low-dose metronomic chemotherapy in dogs-insight into a modern cancer field

The era of chemotherapy, which started in the middle of the last century, has been ruled by the routine use of dose-intense protocols, based on the "maximum-tolerated dose" concept. By promoting a balance between patient's quality of life and the goal of rapidly killing as many tumour cells as possible, these protocols still play a prominent role in veterinary oncology. However, with the opening of a new millennium, metronomic chemotherapy (MC) started to be considered a possible alternative to traditional dose-intense chemotherapy. Characterized by a long-term daily administration of lower doses of cytotoxic drugs, this new modality stands out for its unique combination of effects, namely on neovascularization, immune response and tumour dormancy. This article reviews the rationale for treatment with MC, its mechanism of action and the main studies conducted in veterinary medicine, and discusses the key challenges yet to be solved.

Expression of semaphorin 6D and its receptor plexin-A1 in gastric cancer and their association with tumor angiogenesis

The semaphorin and plexin family of ligands and receptor proteins provides important axon growth and guidance cues required for development. In recent years, studies have expanded their role in the regulation of cardiac morphogenesis and tumorigenesis. However, the mechanism responsible for their role in regulating cancer development and progression has not been clarified. In the present study, semaphorin 6D (Sema6D) and its receptor plexin-A1 were identified to be expressed at high levels in vascular epithelial cells within gastric cancer, and were positively correlated with vascular endothelial growth factor receptor 2 (VEGFR2). These findings verify our hypothesis that Sema6D and plexin-A1 may be closely associated with tumor angiogenesis. Combined with experimental observations in the MGC803 gastric cancer cell line, it was observed that knocking down plexin-A1 signaling led to a decreased expression of VEGFR2 at the messenger RNA and protein levels. Sema6D recognized and activated plexin-A1, which subsequently activated its downstream target, VEGFR2. The activation of VEGFR2 functioned as a positive regulator of tumor angiogenesis. Our data provided an understanding of the complex signaling cascades involved in the angiogenesis-related pathway in tumor cells. In light of our observations, pharmacological interventions targeting Sema6D/plexin-A1/VEGFR2 signaling may potentially be used as a target for the development of novel anti-angiogenic drugs in gastric cancer.

Anti‑angiogenic therapy for normalization of tumor vasculature: A potential effect of Buyang Huanwu decoction on nude mice bearing human hepatocellular carcinoma xenografts with high metastatic potential

The present study aimed to investigate the effect of Buyang Huanwu decoction (BYHWD) on tumor growth, metastasis and angiogenesis in nude mice bearing human hepatocellular carcinoma (HCC) HCCLM3 xenografts. A total of 96 nude mice bearing HCCLM3 xenografts were randomly divided into four groups: BYHWD group (LB), Yi-qi decoction group (LY), Huo-xue decoction group (LH) and model group (LM). Each of these groups was divided into three subgroups (n=8), which were observed on days 21, 25, 38 following treatment, respectively. The tumor weights, volumes and pulmonary metastases were recorded. The expression of CD105 and the microvessel density (MVD) were assessed, and the expression levels of vascular endothelial growth factor (VEGF), hypoxia-inducible factor 1α (HIF-1α), and regulator of G protein signaling 5 (RGS-5) were analyzed using immunohistochemical staining. Compared with the LM group, no significant decrease in tumor weight or volume were observed in the herbal medicine treatment groups, the number of the metastases in the lungs decreased, whereas the expression levels of RGS-5 and HIF-1α decreased in the LB group on day 35. However, the expression levels of VEGF increased in the LB group on days 28 and 35 post-treatment. The results of the present study suggested that BYHWD may inhibit angiogenesis and metastasis by affecting the expression levels of VEGF, RGS-5 and HIF-1α, and suggested that BYHWD may contribute to the tumor microenvironment and vasculature normalization in HCC.

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.

Carboplatin delays mammary cancer 4T1 growth in mice

Carboplatin is commonly used to treat a variety of tumors. We investigated the effects of carboplatin (100mg/kg) in the development and metastatic dissemination of the 4T1 mice mammary carcinoma. Carboplatin was able to reduce tumor volume and the number of lung metastases in 50% compared to the control animals. Mitotic and apoptotic indices were also decreased by the treatment. Assessment of the vascularization of the tumors revealed a significant decrease in blood vessel formation by carboplatin. A decrease in nuclear positivity of CDC47 and cyclin D1 was observed in the group treated with carboplatin when compared to the control group. Positivity for p53 was observed in the control group (2/28; 5%) and the treated group (5/71; 4%). Carboplatin has been demonstrated to be an efficient regulator of 4T1MMT growth and dissemination. The action of this chemotherapeutic agent seems to be related to the induction of apoptosis and inhibition of angiogenesis and cell proliferation.

Palm tocotrienols decrease levels of pro-angiogenic markers in human umbilical vein endothelial cells (HUVEC) and murine mammary cancer cells

Anti-angiogenic therapy is widely being used to halt tumour angiogenesis. In this study, the anti-angiogenic activity of palm tocotrienol-rich fraction (TRF) and its individual components (γ- and δ-tocotrienol) were first investigated in vitro in human umbilical vein endothelial cells (HUVEC) and 4T1 mouse mammary cancer cells. Results showed reduced levels of Interkeukin (IL)-8 and IL-6, two pro-angiogenic cytokines in HUVEC treated with palm tocotrienols compared with α-tocopherol (α-T) and control cells (P < 0.05). The production of IL-8 and IL-6 was lowest in δ-tocotrienol (δ-T3)-treated cells followed by γ-tocotrienol (γ-T3) and TRF. There was significant (P < 0.05) reduction in IL-8 and vascular endothelial growth factor (VEGF) production in 4T1 cells treated with TRF or δ-T3. There was decreased expression of VEGF and its receptors; VEGF-R1 (fms-like tyrosine kinase, Flt-1) and VEGF-R2 (Kinase-insert-domain-containing receptor, KDR/Flk-2) in tumour tissues excised from mice supplemented with TRF were observed. There was also decreased expression of VEGF-R2 in lung tissues of mice supplemented with TRF. These observations correlate with the smaller tumour size recorded in the tocotrienol-treated mice. This study confirms previous observations that palm tocotrienols exhibit anti-angiogenic properties that may inhibit tumour progression.

Characteristic Genotypes of Vascular Endothelial Growth Factor are Susceptible to Ascites in Patients with Cirrhosis

This study was designed to investigate whether different vascular endothelial growth factor (VEGF) genotypes are associated with ascites formation in cirrhotic patients. Seventy cirrhotic patients were included in the study: 25 cirrhotic patients with ascites and 45 cirrhotic patients without ascites. Patient characteristics were investigated and compared between the two groups. With regard to VEGF genotype, 42 patients were C/C and 28 patients were T/T or C/T. The genotypes T/T or C/T were observed in 23 cases (51%) among the non-ascites group, but in only five cases (20%) among the ascites group. Serum levels of albumin and creatinine, and the VEGF genotypes were significantly different between the two groups. Multiple regression analysis showed that serum levels of creatinine and the VEGF genotypes were significantly correlated with ascites formation. Thus, it can be concluded that VEGF genotyping might be a valuable susceptibility marker for ascites formation in cirrhotic patients.

Effect of thalidomide on endotoxin-induced decreases in activity and expression of hepatic cytochrome P450 3A2

Thalidomide has been reported to inhibit the production of tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) that are involved in the down-regulation of hepatic cytochrome P450 (CYP) induced by endotoxin. In the present study, we investigated the effects of thalidomide on endotoxin-induced decreases in the activity and expression of hepatic CYP3A2 in rats. Thalidomide (50 mg/kg) was administered orally 22 h and 2 h before intraperitoneal injection of endotoxin (1 mg/kg). Twenty-four hours after the injection of endotoxin, antipyrine clearance experiments were conducted, in which the rats were sacrificed and protein levels of hepatic CYP3A2 were measured. There were no significant differences in the histopathological changes in the liver between the endotoxin-treated and endotoxin plus thalidomide-treated rats. Thalidomide had no effect on the systemic clearance of antipyrine, which is a proper indicator for hepatic CYP3A2 activity, whereas it enhanced endotoxin-induced decrease in the systemic clearance of antipyrine. Western blot analysis revealed that thalidomide had no effect on the protein levels of hepatic CYP3A2, whereas it enhanced the down-regulation of hepatic CYP3A2 by endotoxin. However, there were no significant differences in the concentrations of TNF-alpha and NO in plasma between the endotoxin-treated and endotoxin plus thalidomide-treated rats. The present findings suggest that thalidomide enhances endotoxin-induced decreases in the activity and expression of hepatic CYP3A2.

Multi-centre phase II trial of Thalidomide in the treatment of unresectable hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a hypervascular tumour, which overexpresses vascular endothelial growth factor. Thalidomide is an antiangiogenic agent with activity in refractory multiple myeloma. The purpose of this multi-centre phase II study was to evaluate the efficacy and toxicity of thalidomide in patients with advanced HCC. From February 2000 to November 2001, 37 patients with histologically proven, bi-dimensionally measurable advanced, unresectable HCC were enrolled. The starting dose of Thalidomide was 100 mg per day and escalated weekly by 100 mg to a maximum dose of 800 mg/day according to individual patient tolerance. Radiological tumour response and treatment related toxicities were prospectively assessed. Thirty-seven patients were evaluable for toxicity and 24 patients were evaluable for response. The median Thalidomide dose was 400 mg/day. There was no complete response (CR). One patient had a radiological partial response (PR) (3%; 95% confidence interval [95% CI], 0% to 8%) and six (16%) patients had stable disease for more than 6 months. Somnolence and fatigue were the most common side effects, occurring in 84% and 73% of patients respectively. Thalidomide monotherapy is tolerable and associated with modest antitumour activity in advanced HCC.

Reversing hepatocellular carcinoma progression by using networked biological therapies

The liver is distinguished from other tissues by (a) its detoxifying function, (b) its resistance to apoptosis, and (c) its regenerative response to damage. Hepatocellular carcinoma arises when chronic insults, such as hepatitis or iron overload, constitutively activate this regenerative program. Here, we propose that the proliferative response of the liver to damage underlies the resistance of hepatocellular carcinoma to cytotoxic therapy, and that hepatocellular carcinoma growth should therefore be more readily controlled by using a networked combination of noncytotoxic interventions to interrupt the damage-inducible regenerative pathway. To this end, hepatocellular carcinoma boasts a wealth of potential drug targets, including viral replication, the antiapoptotic immunosuppressant alpha-fetoprotein, hepatic iron overload, inflammatory signaling, extracellular proteases, and growth factors. By blocking these positive feedback loops in parallel, and so returning the host environment to a more normal state, epigenetic repression of tumor-suppressor gene function may be reversed and tumor dormancy restored. Noncytotoxic maneuvers that short circuit damage resistance loops may thus represent an indirect form of gene therapy meriting incorporation into hepatocellular carcinoma clinical trials.

Expression of angiopoietins, Tie2 and vascular endothelial growth factor in angiogenesis and progression of hepatocellular carcinoma

AIM: To investigate the significance of angiopoietins, Tie2 and vascular endothelial growth factor (VEGF) expression in the angiogenesis and progress of hepatocellular carcinoma (HCC).

METHODS: Fresh surgically resected specimens of HCC and noncancerous liver (NCL) tissue from 38 patients with HCC were obtained, and expression of angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), Tie2, and VEGF messenger RNA (mRNA) was examined by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). Expression pattern of each gene in HCC and NCL tissue specimens was compared and the potential role and interaction in angiogenesis of HCC were analyzed. Genes’ expression level and its relationship with tumor’s clinicopathological parameters were also investigated. Immunohistochemical staining of CD34 was performed to determine the microvessel density (MVD) and Ang-2/Ang-1 ratio was calculated. Relationships between Ang-2/Ang-1 ratio, VEGF and MVD and clinicopathological features were also tested so as to evaluate their significance in the progression of HCC.

RESULTS: Ang-2 and VEGF mRNAs in HCC were significantly higher than those in NCL tissue (P < 0.05), whereas the Ang-1 and Tie2 mRNAs showed no statistical significance (P > 0.05), though slightly lower level of Ang-1 mRNA in HCC was observed. Ang-2/Ang-1 ratio and VEGF were both positively correlated to MVD. The Ang-2/ Ang-1 ratio, Ang-2 and VEGF were all associated with tumor’s clinicopathological parameters (P < 0.05) except for histological grades (P > 0.05). Ang-1 and Tie2 levels in different clinicopathological groups were not significantly different (P > 0.05).

CONCLUSION: Dominant Ang-2 expression against Ang-1 through Tie2 receptor in the presence of VEGF plays a critical role in initiating early neovascularization and transformation of noncancerous liver to hepatocellular carcinoma. Its consequently constant operation in formed HCC induces further angiogenesis and progression of HCC.

Staging and current treatment of hepatocellular carcinoma

Early-stage hepatocellular carcinoma (HCC) is typically clinically silent, and HCC is often advanced at first manifestation. Without treatment, the 5-year survival rate is less than 5%. The selected treatment depends on the presence of comorbidity; tumor size, location, and morphology; and the presence of metastatic disease. Complete surgical resection followed by hepatic transplantation offers the best long-term survival, but few patients are eligible for this therapy. All other therapies are palliative. Radiofrequency ablation is the preferred method for managing unresectable small HCCs that are few in number. More widespread disease is treated with percutaneous therapies such as chemoembolization and selective internal radiation therapy. Systemic administration of biologic and chemotherapeutic agents is minimally successful in slowing the growth of HCC and typically is used to control symptoms in patients with overwhelming disease. A multidisciplinary approach that includes surgery, systemic therapy, and radiation therapy and that is based on the cooperation of radiation oncologists, interventional and diagnostic radiologists, hepatologists, and pathologists may offer the best chance of a cure or at least a longer and more normal life. To participate effectively in this effort, radiologists must be familiar with staging and treatment options for HCC and with the factors that affect the choice of management method.

Blood flow changes in hepatocellular carcinoma after the administration of thalidomide assessed by reperfusion kinetics during microbubble infusion: preliminary results

OBJECTIVES

We sought to investigate whether thalidomide is able to produce tumor vascular changes in patients with untreatable hepatocellular carcinoma (HCC) that can be detected using microbubble contrast agents.

MATERIALS AND METHODS

Eleven consecutive patients with untreatable HCC underwent contrast-enhanced ultrasound before and during thalidomide administration. Real-time destruction reperfusion kinetics was obtained from a representative HCC nodule and from the surrounding liver parenchyma during SonoVue infusion (Bracco, Milan, Italy) at a constant rate of 0.10 mL/s by using a syringe pump and modelized according to the mathematical function SI = A(1 - exp(-betat)) where the plateau signal intensity A reflects the percent blood volume, the time constant beta reflects the average speed of blood, and their product A*beta reflects the nutrient blood flow.

RESULTS

Size of the representative nodule reduced significantly 3 to 6 months after the start of thalidomide treatment. Before thalidomide administration A, beta, and A*beta of the index lesion were 44 +/- 60 LIU, 0.31 +/- 0.40 seconds and 8.1 +/- 11.8 LIU/s, respectively). A and A*beta reduced significantly after 15 days (26 +/- 50 LIU and 2.9 +/- 4.8 LIU/s, P < 0.01), 3 months (12 +/- 18 LIU, and 4.3 +/- 7.7 LIU/s, P < 0.01), and 6 months (13 +/- 23 LIU and 2.4 +/- 3.7 LIU/s, P < 0.05) of treatment. No statistically significant changes of the exponential time constant beta were observed, nor changes of A, beta and A*beta in the liver parenchyma.

CONCLUSIONS

Contrast-enhanced ultrasound can be used effectively to evaluate changes in perfusion parameters of HCC nodules during thalidomide administration.

Thalidomide enhances the anti-tumor activity of standard chemotherapy in a human melanoma xenotransplatation model

It has been demonstrated that thalidomide's anti-angiogenic properties result in clear anti-tumor activity in a number of human malignancies. We studied thalidomide in a human melanoma severe combined immunodeficiency mouse xenotransplantation model. Thalidomide as a single agent showed a significant tumor reduction of 46% compared with the control group. Thalidomide combined with dacarbazine treatment markedly enhanced the anti-tumor effect of chemotherapy and showed a significant tumor reduction relative to the dacarbazine-only group (61%) and even more tumor reduction (74%) compared with the control group. We also measured clearly reduced levels of tumor necrosis factor-alpha in the thalidomide-treated group. A significantly lower microvessel density was encountered in the thalidomide treatment groups (thalidomide alone or combined with DTIC), underscoring the anti-angiogenic effect of thalidomide as a single agent as well as in combination with chemotherapy in this model. In line with these results, we observed a nearly 3-fold increase of apoptosis for the combination of thalidomide and DTIC compared with the rate of apoptotic cells in DTIC-only-treated melanoma xenotransplants. These data underline the rationale for combining dacarbazine--a cytotoxic agent--and thalidomide--an anti-angiogenic cytostatic agent--as a promising strategy for the treatment of melanoma.