Thalidomide as an anti-cancer agent

Association between Immunosuppressive Therapy Utilized in the Treatment of Autoimmune Disease or Transplant and Cancer Progression

Autoimmunity and cancer rates have both been on the rise in Western civilization prompting many to investigate the link between the two entities. This review will investigate the complex interactions between the activation and deactivation of the immune system and the development of malignancy. Additional focus will be placed on the main classes of immune inhibitor therapy utilized in transplant patients and in autoimmune disease including TNF-alpha, Calcineurin, mTOR, purine synthesis antagonists and IMPDH inhibitors.

The role of thalidomide in dermatology

Thalidomide is a medication that has been in existence for over half a century, and has proven to be useful and effective in severe dermatological conditions. For dermatologists, the ability of thalidomide to reduce the levels of the cytokine tumour necrosis factor-α, along with its immunomodulatory and anti-angiogenic properties, is of great significance, with the added advantage of being an oral medication. Its use is of course strictly monitored, owing to its potential adverse effects (AEs), particularly teratogenicity, with precautions taken to ensure its safe and correct use by both prescriber and patient. In this review, we look at the background and mechanism of action of thalidomide, provide an overview of conditions it can be used for with case examples, explain the potential AEs and monitoring requirements, and discuss future developments.

Cancer cachexia has many symptoms but only one cause: anoxia

During nearly 100 years of research on cancer cachexia (CC), science has been reciting the same mantra: it is a multifactorial syndrome. The aim of this paper is to show that the symptoms are many, but they have a single cause: anoxia. CC is a complex and devastating condition that affects a high proportion of advanced cancer patients. Unfortunately, it cannot be reversed by traditional nutritional support and it generally reduces survival time. It is characterized by significant weight loss, mainly from fat deposits and skeletal muscles. The occurrence of cachexia in cancer patients is usually a late phenomenon. The conundrum is why do similar patients with similar tumors, develop cachexia and others do not? Even if cachexia is mainly a metabolic dysfunction, there are other issues involved such as the activation of inflammatory responses and crosstalk between different cell types.  The exact mechanism leading to a wasting syndrome is not known, however there are some factors that are surely involved, such as anorexia with lower calorie intake, increased glycolytic flux, gluconeogenesis, increased lipolysis and severe tumor hypoxia. Based on this incomplete knowledge we put together a scheme explaining the molecular mechanisms behind cancer cachexia, and surprisingly, there is one cause that explains all of its characteristics: anoxia.  With this different view of CC we propose a treatment based on the physiopathology that leads from anoxia to the symptoms of CC.  The fundamentals of this hypothesis are based on the idea that CC is the result of anoxia causing intracellular lactic acidosis. This is a dangerous situation for cell survival which can be solved by activating energy consuming gluconeogenesis. The process is conducted by the hypoxia inducible factor-1α. This hypothesis was built by putting together pieces of evidence produced by authors working on related topics.

Synthesis, characterization, and anticancer activity of folate γ-ferrocenyl conjugates

Novel folate γ-ferrocene conjugates were synthesized through a regiospecific route, and showed selectivity and enhanced cytotoxicity against Frα-positive malignant cells.

Trifunctionalization of alkenes and alkynes

In this review, the development of trifunctionalization methods for alkenes and alkynes, including arynes and allenes, over the last decade is disclosed.

Crystal structure of the thalidomide analog (3aR*,7aS*)-2-(2,6-dioxopiperidin-3-yl)hexa-hydro-1H-iso-indole-1,3(2H)-dione

The title compound, C13H16N2O4, crystallizes in the monoclinic centrosymmetric space group, P21/c, with four mol-ecules in the asymmetric unit, thus there is no crystallographically imposed symmetry and it is a racemic mixture. The structure consists of a six-membered unsaturated ring bound to a five-membered pyrrolidine-2,5-dione ring N-bound to a six-membered piperidine-2,6-dione ring and thus has the same basic skeleton as thalidomide, except for the six-membered unsaturated ring substituted for the aromatic ring. In the crystal, the mol-ecules are linked into inversion dimers by R 2 2(8) hydrogen bonding involving the N-H group. In addition, there are bifurcated C-H⋯O inter-actions involving one of the O atoms on the pyrrolidine-2,5-dione with graph-set notation R 1 2(5). These inter-actions along with C-H⋯O inter-actions involving one of the O atoms on the piperidine-2,6-dione ring link the mol-ecules into a complex three-dimensional array. There is pseudomerohedral twinning present which results from a 180° rotation about the [100] reciprocal lattice direction and with a twin law of 1 0 0 0 0 0 0 [BASF 0.044 (1)].

Pitfalls of Combining Novel Agents in Lymphoma

OPINION STATEMENT

As our knowledge of lymphoma and its intricate signaling pathways has grown, so has the development of novel agents. While their mechanisms of action vary considerably, these therapies supplement and in some cases offer alternatives to standard chemotherapy. Initial studies have highlighted tolerable side effects though in the majority of instances limited efficacy when used as monotherapy. Research has focused on combining these novel agents to improve outcomes and perhaps offer refined treatment options. Novel combinations represent new territory, inherently dissimilar to combination chemotherapy with new pitfalls and challenges given their unique mechanisms of action. Though promising, it is crucial to consider the complex interplay that can occur. While there is potential for improved outcomes, there is also the possibility of unexpected toxicities. For this reason, it is critical that novel combinations be carefully considered and tested in clinical trials before widespread use. Thus far, research has shown that combination therapies are successful when not only avoiding overlapping toxicity but also capitalizing on synergy. We believe that more specific targets and an improved understanding of their off-/on-target effects will further successful novel combinations.

Drug repurposing in cancer

Cancer is a major health issue worldwide, and the global burden of cancer is expected to increase in the coming years. Whereas the limited success with current therapies has driven huge investments into drug development, the average number of FDA approvals per year has declined since the 1990s. This unmet need for more effective anti-cancer drugs has sparked a growing interest for drug repurposing, i.e. using drugs already approved for other indications to treat cancer. As such, data both from pre-clinical experiments, clinical trials and observational studies have demonstrated anti-tumor efficacy for compounds within a wide range of drug classes other than cancer. Whereas some of them induce cancer cell death or suppress various aspects of cancer cell behavior in established tumors, others may prevent cancer development. Here, we provide an overview of promising candidates for drug repurposing in cancer, as well as studies describing the biological mechanisms underlying their anti-neoplastic effects.

Thalidomide reduces mechanical hyperalgesia and depressive-like behavior induced by peripheral nerve crush in mice

BACKGROUND

It has been shown that chronic pain is able to induce depressive disorders in humans, in part, due to peripheral inflammation that reaches the central nervous system. However, the mechanisms involved remain to be established. The purpose of this study was to investigate whether sciatic nerve crush could produce depression-like behaviors, in addition to pain-related behaviors, in mice. Once confirmed, this model was used to investigate tumor necrosis factor-α (TNF-α) as a key mediator involved in the pathophysiology of both pain and depression.

EXPERIMENTAL APPROACH

Male Swiss mice were divided into three groups, naïve, sham and operated. In the operated group, the sciatic nerve was crushed. Following surgery, animals from the operated group were treated daily by oral gavage (p.o.) with saline (10 ml/kg), fluoxetine (20 mg/kg) or thalidomide (10 mg/kg) for 15 days. Mechanical hyperalgesia was evaluated every 3 days by von Frey filaments and depressive-like behavior was assessed at the end of day 15, using the tail suspension test (TST) and the forced swimming test (FST). Then, samples from the prefrontal cortex, hippocampus and sciatic nerve were processed to measure TNF-α levels by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Crush caused significant mechanical hyperalgesia and depressive-like behaviors and increased TNF-α levels in the sciatic nerve, prefrontal cortex and hippocampus of operated animals. Treatment with fluoxetine or thalidomide reversed crush-induced mechanical hyperalgesia, depressive-like behaviors and the increased TNF-α levels in the sciatic nerve, prefrontal cortex and hippocampus.

CONCLUSIONS

The sciatic nerve crush model represents a good model to study to mechanisms underlying both pain and depressive-like behaviors. Furthermore, inhibitors of TNF-α synthesis, like thalidomide, have a potential to treat depressive disorders associated with neuropathic pain.

Lenalidomide in relapsed or refractory mantle cell lymphoma: overview and perspective

Lenalidomide, a novel immunomodulatory agent, was approved by the US Food and Drug Administration for the treatment of myelodysplastic syndrome and relapsed multiple myeloma. Data from preclinical studies paved the way for clinical trials of lenalidomide in mantle cell lymphoma (MCL). Initial phase I and II clinical trials of lenalidomide alone and as part of combination regimens in patients with relapsed/refractory MCL have shown promising results. Its immunomodulatory, T cell costimulatory, anti-inflammatory and anti-angiogenic actions working together in the tumor cell microenvironment seem to be responsible for its enhanced antitumor efficacy. Lenalidomide's nature of action and safety profile favor it over other agents studied in relapsed/refractory MCL. This review summarizes the data from preclinical and clinical studies of lenalidomide in relapsed/refractory MCL and compares the results with those of other novel agents being used for relapsed/refractory MCL.

Antiangiogenic strategies in hepatocellular carcinoma: current status

Hepatocellular carcinoma is a leading cause of cancer death worldwide in both adult and pediatric patients. Despite many options, no ideal treatment exists for this highly malignant tumor, and management strategies have varied accordingly. Angiogenesis, the formation of new blood vessels, is an essential component of hepatocellular carcinoma biology. Innovative approaches such as targeting the nontransformed, less resistant, tumor-supporting endothelial cells are currently under investigation in hepatocellular carcinoma. This review will focus on the current knowledge of the pathophysiology of hepatocellular carcinoma angiogenesis, as well as the reported data with angiogenesis inhibitors against hepatocellular carcinoma.

Anticancer metallodrugs of glutamic acid sulphonamides: in silico, DNA binding, hemolysis and anticancer studies

In response to an increased demand for effective anticancer drugs, a series of disodium sulphonamides ofl-glutamic acid (L1–L3) was synthesized. Sulphonamides were complexed with copper(ii), nickel(ii) and ruthenium(iii) ions, separately and respectively.

Glutamic acid and its derivatives: candidates for rational design of anticancer drugs

Throughout the history of human civilizations, cancer has been a major health problem. Its treatment has been interesting but challenging to scientists. Glutamic acid and its derivative glutamine are known to play interesting roles in cancer genesis, hence, it was realized that structurally variant glutamic acid derivatives may be designed and developed and, might be having antagonistic effects on cancer. The present article describes the state-of-art of glutamic acid and its derivatives as anticancer agents. Attempts have been made to explore the effectivity of drug-delivery systems based on glutamic acid for the delivery of anticancer drugs. Moreover, efforts have also been made to discuss the mechanism of action of glutamic acid derivatives as anticancer agents, clinical applications of glutamic acid derivatives, as well as recent developments and future perspectives of glutamic acid drug development have also been discussed.

Isosteric analogs of lenalidomide and pomalidomide: synthesis and biological activity

A series of analogs of the immunomodulary drugs lenalidomide (1) and pomalidomide (2), in which the amino group is replaced with various isosteres, was prepared and assayed for immunomodulatory activity and activity against cancer cell lines. The 4-methyl and 4-chloro analogs 4 and 15, respectively, displayed potent inhibition of tumor necrosis factor-α (TNF-α) in LPS-stimulated hPBMC, potent stimulation of IL-2 in a human T cell co-stimulation assay, and anti-proliferative activity against the Namalwa lymphoma cell line. Both of these analogs displayed oral bioavailability in rat.

Targeting of the innate immunity/inflammation as complementary anti-tumor therapies

Different types of cancer take advantage of inflammatory components to improve their life-span in the organs. A sustenance of growth factors and cytokines (e.g. interleukin (IL)-1, tumor necrosis factor, IL-6, vascular endothelial growth factor) supports malignant cell progression and contributes to suppress the body immune defense. Strategies to modulate the host micro-environment offer new approaches for anti-cancer therapies. For these reasons new molecules with anti-tumor and anti-inflammatory features (e.g. trabectedin) are looked at with new eyes in the light of the crucial link between inflammation and cancer.

Harnessing tumor necrosis factor receptors to enhance antitumor activities of drugs

Cancer is the second-leading cause of death in the U.S. behind heart disease and over stroke. The hallmarks of cancer comprise six biological capabilities acquired during the multistep development of human tumors. The inhibition of cell death pathways is one of these tumor characteristics which also include sustained proliferative signaling, evading growth suppressor signaling, replicative immortality, angiogenesis, and promotion of invasion and metastasis. Cell death is mediated through death receptor (DR) stimulation initiated by specific ligands that transmit signaling to the cell death machinery or through the participation of mitochondria. Cell death involving DR is mediated by the superfamily of tumor necrosis factor receptor (TNF-R) which includes TNF-R type I, CD95, DR3, TNF-related apoptosis-inducing ligand (TRAIL) receptor-1 (TRAIL-R1) and -2 (TRAIL-R2), DR6, ectodysplasin A (EDA) receptor (EDAR), and the nerve growth factor (NGF) receptor (NGFR). The expression of these receptors in healthy and tumor cells induces treatment side effects that limit the systemic administration of cell death-inducing therapies. The present review is focused on the different therapeutic strategies such as targeted antibodies or small molecules addressed to selective stimulated DR-mediated apoptosis or reduce cell proliferation in cancer cells.

Thalidomide affects the skeletal system of ovariectomized rats

Apart from having written an inglorious chapter in the history of medicine, thalidomide is currently being intensely studied because of its multidimensional activity. The aim of this study was to examine the effects of thalidomide on the skeletal system in ovariectomized and non-ovariectomized rats. The experiments were carried out with female Wistar rats, divided into eight groups: sham-operated control rats; sham-operated rats receiving thalidomide at doses of 15, 30 or 60 mg/kg, po; ovariectomized control rats; ovariectomized rats receiving thalidomide at doses of 15, 30 or 60 mg/kg, po. The drug was administered for 4 weeks. Body mass gain and the mass of the uterus, liver, spleen and thymus were studied. Macrometric parameters and content of mineral substances, calcium and phosphorus in the femur, tibia and L-4 vertebra and histomorphometric parameters of the femur and tibia were examined. In the femur, the mechanical properties of the whole bone and of the femoral neck were examined. Thalidomide did not affect the skeletal system of the non-ovariectomized rats. Bilateral ovariectomy induced osteoporotic skeletal changes in mature female rats. The effects of thalidomide on the skeletal system of ovariectomized rats depended on the dose used. With a dose of 15 mg/kg, po, thalidomide counteracted some osteoporotic changes induced by estrogen deficiency. With a dose of 60 mg/kg, po, thalidomide intensified the destructive effects of estrogen deficiency on the rat skeletal system.

On the effect of thalidomide on Mycobacterium avium subspecies paratuberculosis in culture

BACKGROUND

Without known mechanisms of action, thalidomide is used to treat a variety of non-malignant 'idiopathic' diseases. There is increasing concern that Mycobacterium avium subspecies paratuberculosis (MAP) may be zoonotic. Recently, methotrexate, azathioprine, 6-mercaptopurine (6-MP), 5-aminosalicylic acid (5-ASA), cyclosporine A, rapamycin, and tacrolimus have been shown to inhibit MAP growth in culture, indicating that, unknowingly, MAP infections may have been treated for decades. We herein test the hypothesis that thalidomide may inhibit MAP growth.

METHODS

Using the radiometric 14CO2 (Bactec) system we quantified growth kinetics of thalidomide (+/-), (+), and (-) and two components for thalidomide, phthalimide and 1-hydroxypiperidine-2,6-dione (HPD). We studied four MAP strains (three human isolates, 'Ben', 'Dominic', and UCF-4, and a bovine MAP isolate 19698) and three mycobacterial controls (Mycobacterium avium and bacillus Calmette-Guérin (BCG)). Growth was quantified as growth index (GI) and inhibition as percent decrease in cumulative GI (%-DeltacGI).

RESULTS

Phthalimide had no dose-dependent inhibition on any strain. Neither thalidomide nor HPD inhibited M. avium or BCG. MAP inhibition varied; at 64 microg/ml, amongst human isolates, Dominic was most susceptible: thalidomide (+)=58%-DeltacGI and HPD=46%-DeltacGI. UCF-4 was next: thalidomide (-)=37%-DeltacGI and HPD=40%-DeltacGI. Ben was least susceptible: HPD=24%-DeltacGI.

CONCLUSIONS

We have shown, in culture, the heretofore-undescribed inhibition of MAP growth by thalidomide and its enantiomers. Phthalimide was found to have no anti-MAP activity, whereas HPD was found to inhibit MAP growth. These data are compatible with the hypothesis that thalidomide, like other 'anti-inflammatories' and 'immunomodulators' may act, in part, as an anti-MAP antibiotic.

TNF-alpha and its inhibitors in cancer

Tumor necrosis factor (TNF)-alpha is implicated in the same time in apoptosis and in cell proliferation. TNF-alpha not only acts as pro-inflammatory cytokine conducing to wide spectrum of human diseases including inflammatory diseases, but can also induce tumor development. The molecular mechanisms of TNF-alpha functions have been intensively investigated. In this review we covered TNF-alpha, the molecule, its signaling pathway, and its therapeutic functions. We provide a particular insight in its paradoxical role in tumor promotion and in its use as anti-tumor agent. This review considers also the recent findings regarding TNF-alpha inhibitors, their pharmacokinetics, and their pharmacodynamics. Six TNF-alpha inhibitors have been considered here: Infliximab, Adalimumab, Golimumab, CDP870, CDP571, Etanercept, and Thalidomide. We discussed the clinical relevance of their functions in treatment of several diseases such as advanced inflammatory rheumatic and bowel disease, with a focus in cancer treatment. Targeting TNF-alpha by these drugs has many side effects like malignancies development, and the long-term sequels are not very well explored. Their efficacy and their safety were discussed, underscoring the necessity of close patients monitoring and of their caution use.

Off-label prescribing: a call for heightened professional and government oversight

Under current U.S. law, physicians may prescribe drugs and devices in situations not covered on the label approved by the Food and Drug Administration. Those supporting this system say that requiring FDA approval for off-label uses would unnecessarily impede the delivery of benefits to patients. Patients do benefit from off-label prescribing that is supported by sound scientific and medical evidence. In the absence of such evidence, however, off-label prescribing can expose patients to risky and ineffective treatments. The medical community and federal authorities should more actively promote patients' interests in receiving beneficial off-label treatments. To exercise responsible self-regulation, members of the medical community must determine whether available evidence justifies specific off-label uses and must promote information-gathering when the evidence is inadequate. Physicians should also discuss with patients the uncertainties accompanying off-label uses. Federal authorities should more closely monitor the effects of off-label prescribing and adopt other measures to reduce harm and enhance benefits produced by off-label prescribing.

Analysis of herpes zoster events among bortezomib-treated patients in the phase III APEX study

PURPOSE

The aim of this subset analysis was to determine if bortezomib treatment is associated with increased incidence of varicella-zoster virus (VZV) reactivation in patients with relapsed multiple myeloma (MM).

PATIENTS AND METHODS

Incidence of herpes zoster was evaluated in 663 patients with relapsed MM from the phase III APEX trial comparing single-agent bortezomib with high-dose dexamethasone.

RESULTS

Bortezomib was associated with a significantly higher incidence of herpes zoster compared with dexamethasone treatment (13%, 42 of 331 v 5%, 15 of 332; P = .0002). Most herpes zoster infections were grade 1/2; incidences of grade 3/4 events (1.8% v 1.5%) and infections considered serious adverse events (1.5% v 0.9%) were similar between treatment arms, and no herpes zoster-related deaths occurred. Neither the time to onset of the herpes event nor the patients' absolute lymphocyte counts at baseline differed significantly between arms. VZV reactivation was the only herpes viral event noted to be significantly elevated in the bortezomib treatment group compared with the dexamethasone treatment group (P = .0002). The incidence of non-VZV-related herpes viral infections was comparable between arms. No additional risk factors for herpes zoster reactivation were identified.

CONCLUSION

Further studies are needed to explain these observations and their implications; however, for patients treated with bortezomib or bortezomib-containing regimens, the risk of VZV reactivation should be monitored and routine use of antiviral prophylaxis considered.

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.

State of the art chemotherapeutic management of pediatric brain tumors

CNS tumors are the most common solid tumor of childhood. This article will review current treatments for pediatric brain tumors; low-grade gliomas, high-grade gliomas, medulloblastomas and ependymomas. It will also highlight the treatments that are used for brain tumors in very young children and in children with recurrent brain tumors. The management of recurrent pediatric brain tumors unresponsive to standard therapy will be discussed. The agents used in this setting are mainly biological modifiers, which attempt to provide molecularly targeted therapy. Future directions of therapy for pediatric brain tumors are described. Future treatment paradigms will need to consider examining the use of multiple biological modifiers. Similarly, these agents will need to be examined in combination with cytotoxic chemotherapy. Finally, the future direction of pediatric neuro-oncology and the focus of the field as it battles pediatric brain tumors is discussed.

The treatment of high grade gliomas and diffuse intrinsic pontine tumors of childhood and adolescence: a historical - and futuristic - perspective

Pediatric high grade gliomas represent a heterogeneous group of tumors with poor prognoses despite the use of multimodal treatment. Very little progress has been made over the past decades in identifying efficacious therapeutic modalities against both high grade gliomas and diffuse brainstem gliomas in children. The degree of surgical resection is the most important clinical prognostic factor for children with high grade gliomas, and a complete resection should be attempted whenever feasible. The role of radiation therapy in the treatment of older children with high grade gliomas and diffuse brain stem gliomas is undisputed; however the benefit of using radiation for patients less than 6 years of age (with high grade gliomas) might be questionable. Despite the absence of solid evidence to support its use, chemotherapy is routinely used against these tumors. Currently temozolomide is being investigated due to its activity in adult trials and based on preliminary data regarding recurrent disease. A small subgroup of patients can be successfully treated with high dose chemotherapy followed by autologous stem cell rescue. Early trials using this modality in the past had been associated with high morbidity and mortality. High dose chemotherapy with autologous stem cell rescue in selected patients with minimal residual disease, angiogenesis inhibitors, radiosensitizers and other biological modifiers are being currently investigated in phase I/II trials.

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.

Effect of thalidomide on colorectal cancer liver metastases in CBA mice

BACKGROUND AND AIMS

Thalidomide has undergone resurgence in the treatment of specific malignancies. One of the possible actions of thalidomide may be an antiangiogenic effect. This study investigates the effects of thalidomide on tumor growth and long-term survival in a murine model of colorectal liver metastases.

METHODS

Liver metastases were produced in male CBA mice by intrasplenic injection of a dimethyl hydrazine induced MoCR colon cancer murine cell line. Thalidomide was administered daily at doses ranging from 50 to 300 mg/kg by intraperitoneal injection. Tumor growth was assessed using quantitative stereological analysis. The effect on long-term survival was determined at the maximum tolerated dose using Kaplan-Meier analysis. The microvascular effects of thalidomide were assessed by laser Doppler flowmetry (LDF) and microvascular resin casting. Immunohistochemistry was used to determine vascular endothelial growth factor (VGEF) and basic fibroblast growth factor (bFGF) expression.

RESULTS

Thalidomide, (50-300 mg/kg) caused no significant reduction in tumor growth by day 21 following induction of liver metastases and caused systemic toxicity at a dose of 300 mg/kg. At a dose of 200 mg/kg given beyond 35 days, thalidomide significantly reduced tumor growth compared to control, (P = 0.029). No significant impact on survival was however observed (P = 0.93). LDF and microvascular resin casting showed no differences in blood flow or tumor microvascular architecture. VGEF and FGF were expressed in tumors, but remained unaltered by thalidomide administration compared to matched controls.

CONCLUSIONS

Thalidomide caused a significant reduction in the volume of colorectal liver metastases during the late phase of tumor growth. There was however no improvement in survival. Tumor growth reduction in this model did not appear to be due to microvascular changes or altered expression of VGEF or basic FGF. Further investigation into potential mechanisms of action of thalidomide and its synergistic use with other therapies is required.

Inflammation-associated cancer: NF-kappaB is the lynchpin

It has long been suspected that NF-kappaB signaling has a pivotal role in chronic inflammation-associated malignancies, although genetic evidence for this hypothesis has been lacking. However, recent papers have lent credence to this concept and show that NF-kappaB activation in pre-malignant cells contributes to cell survival and metastatic potential. Furthermore, NF-kappaB activation in tumor-associated leukocytes, especially macrophages, contributes towards tumorigenesis by upregulating tumor-promoting proinflammatory proteins. This emphasizes the importance of NF-kappaB inhibitors as immunotherapeutic agents for chronic inflammation and suggests that these reagents might prevent, or at least inhibit, chronic inflammation-associated tumorigenesis.

Thalidomide: an old drug with new clinical applications

Thalidomide has several targets and mechanisms of action: a hypnosedative effect, several immunomodulatory properties with an effect on the production of TNF-alpha and the balance between the different lymphocyte subsets and an antiangiogenic action. Thalidomide has been used in several cutaneous inflammatory disorders (e.g., erythema nodosum leprosum in lepromatous leprosy, cutaneous lupus erythematosus and severe aphtosis), cancers (e.g., relapsed/refractory multiple myeloma, malignant melanoma and systemic signs in cancer) and inflammatory conditions (e.g., Crohn's disease and rheumatoid arthritis). Several side effects are associated with thalidomide. Some are major, such as teratogenicity, peripheral neuropathy and deep vein thrombosis. Somnolence and rash are frequently reported when thalidomide is used at higher doses as an anticarcinogenic agent and can lead to dose reduction or treatment discontinuation depending on severity. Minor side effects include abdominal pain and endocrine disturbances. To prevent the teratogenicity, use of thalidomide is strictly controlled in western countries with close adherence to a birth control programme. Close monitoring for early development of peripheral neuropathy is also recommended.

Concurrent determination of thalidomide in rat blood, brain and bile using multiple microdialysis coupled to liquid chromatography

A rapid and sensitive system of liquid chromatography coupled with microdialysis was developed for the simultaneous determination of unbound thalidomide in rat blood, brain and bile for pharmacokinetic study. Microdialysis probes were concurrently inserted into the jugular vein toward the right atrium, the brain striatum and the bile duct of the anesthetized Sprague-Dawley rats for biological fluid sampling after the administration of thalidomide (5 mg kg(-1)) through the femoral vein. Thalidomide and dialysates were separated using a Zorbax ODS C(18) column and a mobile phase comprising acetonitrile-methanol-0.1 mm 1-octanesulufonic acid (32:3:65, v/v/v, pH 5.3) at flow rate of 1 mL min(-1). The UV wavelength was set at 220 nm. The concentration-response relationship was linear (r(2)>0.995) over a concentration range of 0.025--25 microg mL(-1). The intra-assay and inter-assay precision and accuracy of thalidomide fell within 7%. The average in vivo recoveries were 0.31+/- 0.02,0.046+/- 0.004 and 0.57+/- 0.02 (n=6), respective to the dialysates of blood, brain and bile, with thalidomide at concentrations 2, 5 and 10 microg mL(-1). The disposition of thalidomide in the blood, brain and bile fluid suggests that there is a rapid thalidomide exchange and equilibration between the blood and brain systems. In addition, thalidomide undergoes hepatobiliary excretion.

5-N-Substituted-2-(substituted benzenesulphonyl) glutamines as antitumor agents. Part II: Synthesis, biological activity and QSAR study

Cancer is a major killer disease throughout human history. Thus, cancer becomes a major point of interest in life science. It was proved that cancer is a nitrogen trap and tumor cells are avid glutamine consumers. The non-essential amino acid glutamine, which is a glutamic acid derivative, supplies its amide nitrogen to tumor cells in the biosynthesis of purine and pyrimidine bases of nucleic acids as well as takes part in protein synthesis. Based on these and in continuation of our composite programme of development of new potential anticancer agents through rational drug design, 17 new 5-N-Substituted-2-(substituted benzenesulphonyl) glutamines were selected for synthesis. These compounds as well as 36 earlier synthesized glutamine analogues were screened for antitumor activity using percentage inhibition of tumor cell count as the activity parameter. QSAR study was performed with 53 compounds in order to design leads with increased effectiveness for antitumor activity using both physicochemical and topological parameters. QSAR study showed that steric effect on the aromatic ring is conducive to the activity. n-butyl substitution on aliphatic side chain and atom no 12 is important for antitumor activity of glutamine analogues.

Alpha-fluoro-substituted thalidomide analogues

Thalidomide, (1), has made a remarkable comeback from its days of a sedative with teratogenic properties due to its ability to selectively inhibit TNF-alpha, a key pro-inflammatory cytokine and its clinical benefit in the treatment of cancer. Thalidomide contains one chiral center and is known to be chirally unstable under in vitro and in vivo conditions. It has been hypothesized that different biological properties are associated with each isomer. Thus, chirally stable analogues of thalidomide, alpha-fluorothalidomide, (3) and alpha-fluoro-4-aminothalidomide (4) were prepared by electrophilic fluorination. Analogue 3 was found to be cytotoxic and did not inhibit TNF-alpha production in LPS stimulated hPBMC below toxic concentrations. On the other hand, 4 was non-cytotoxic at the tested concentrations and was found to be 830-fold more potent than thalidomide as TNF-alpha inhibitor.

Thiothalidomides: novel isosteric analogues of thalidomide with enhanced TNF-alpha inhibitory activity

Thalidomide is being increasingly used in the clinical management of a wide spectrum of immunologically-mediated and infectious diseases, and cancers. However, the mechanisms underlying its pharmacological action are still under investigation. In this regard, oral thalidomide is clinically valuable in the treatment of erythema nodosum leprosum (ENL) and multiple myeloma and effectively reduces tumor necrosis factor-alpha (TNF-alpha) levels and angiogenesis in vivo. This contrasts with its relatively weak effects on TNF-alpha and angiogenesis in in vitro studies and implies that active metabolites contribute to its in vivo pharmacologic action and that specific analogues would be endowed with potent activity. Our focus in the structural modification of thalidomide is toward the discovery of novel isosteric active analogues. In this regard, a series of thiothalidomides and analogues were synthesized and evaluated for their TNF-alpha inhibitory activity against lipopolysacharide (LPS)-stimulated peripheral blood mononuclear cells (PBMC), This was combined with a PBMC viability assay to differentiate reductions in TNF-alpha secretion from cellular toxicity. Two isosteric analogues of thalidomide, compounds 15 and 16, that mostly reflect the parent compound, together with the simple structure, dithioglutarimide 19, potently inhibited TNF-alpha secretion, compared to thalidomide, 1. The mechanism underpinning this most likely is posttranscriptional, as each of these compounds decreased TNF-alpha mRNA stability via its 3'-UTR. The potency of 19 warrants further study and suggests that replacement of the amide carbonyl with a thiocarbonyl may be beneficial for increased TNF-alpha inhibitory action. In addition, an intact phthalimido moiety appeared to be requisite for TNF-alpha inhibitory activity.

The role of immunomodulatory drugs in multiple myeloma

Thalidomide has shown promise in the treatment of newly diagnosed multiple myeloma and relapsed/refractory disease, but side effects such as somnolence, constipation, and neuropathy limit its use. CC-5013, an immunomodulatory drug (IMiD), is more potent than thalidomide. CC-5013 has various immunomodulatory effects, including growth arrest or apoptosis of drug-resistant myeloma cell lines and inhibition of binding of myeloma cells to bone marrow stromal cells. Clinically, 17 of 24 patients (71%) with relapsed/refractory disease experienced a reduction of paraprotein of > or = 25% following treatment with CC-5013, including 11 who had a history of treatment with thalidomide. Another two experienced stable disease. Median time to best response was 2 months (range, 1 to 11) and median duration was 6 months (range, 2 to 18). Grade 3 thrombocytopenia was seen in 20% of patients; grade 3 neutropenia was seen in 60%; and grade 4 neutropenia was seen in 16%. CC-5013 use was not associated with somnolence, constipation, or neuropathy. This article reviews thalidomide in multiple myeloma, the effects of thalidomide analogues IMiDs, and the preclinical and clinical data on CC-5013 in relapsed/refractory multiple myeloma.

Management of thalidomide toxicity

Thalidomide has re-emerged as a novel antineoplastic agent with immunomodulatory and antiangiogenic activities. In the early sixties, it was withdrawn from the market after its infamous association with congenital abnormalities that left about 10,000 children affected world-wide. With strict regulations and precautions, thalidomide is now approved by the FDA for the treatment of erythema nodosum leprosum. Its role in cancer therapy is promising, with clinical trials in the past 5 years showing significant activity in multiple myeloma. Several trials are ongoing in other malignancies, such as myelodysplastic syndrome, agnogenic myeloid metaplasia, renal cell carcinoma, and prostate cancer. The major toxicities of thalidomide are birth defects, sensorimotor peripheral neuropathy, somnolence, rash, fatigue, and constipation. Less common side effects include deep venous thrombosis, Stevens-Johnson syndrome, elevated liver enzymes, malaise, and peripheral edema. The incidence and severity of adverse events are related to dose and duration of therapy. Doses of the drug of 200 mg/day or less are usually well tolerated. In this review, we will discuss the incidence and management of the side effects of thalidomide and the precautions and interventions needed to minimize the toxicities of this drug.

Matrix metalloproteinase regulation of sphingosine-1-phosphate-induced angiogenic properties of bone marrow stromal cells

OBJECTIVE

Bone marrow-derived stromal cells (MSC) are able to acquire histological and immunophenotypic characteristics consistent with endothelial cells (EC). In this study we examined the effect of sphingosine-1-phosphate (S1P), a platelet-derived bioactive lysophospholipid that is believed to specifically stimulate EC migration and tube formation, on the angiogenic properties of MSC.

METHODS

MSC were isolated from murine bone marrow and cultured in the presence of diverse angiogenic growth factors. Using a chemotaxis chamber and Matrigel tubulogenesis assay, we measured the extent of MSC migration and capillary-like structure formation. Western blots and zymography were used to assess the levels and activation states of soluble and membrane-bound matrix metalloproteinase (MMP).

RESULTS

We found that S1P strongly induced MSC migration and in vitro capillary-like structure formation. Ilomastat, a broad-spectrum MMP inhibitor, antagonized several angiogenic and S1P-mediated events in MSC. These included 1) the inhibition of S1P-induced tube formation, 2) the inhibition of concanavalin-A (Con-A)-mediated proMMP-2 activation, and 3) the inhibition of S1P- and Con-A-induced caspase-3 activity. Moreover, S1P induced membrane type-1 (MT1)-MMP mRNA and protein expression, but paradoxically antagonized its cell surface proteolytic processing. In addition, anti-angiogenic agents such as Ilomastat, Neovastat, and green tea polyphenol epigallocatechin-3-gallate antagonized the S1P-induced migration of MSC as well as that of transfected COS-7 cells overexpressing the recombinant receptor for S1P, EDG-1.

CONCLUSION

Collectively, our results indicate a crucial role for S1P/EDG-1-mediated angiogenic and survival events in the regulation of microvascular network remodeling by MSC, and may provide a new molecular link between hemostasis and angiogenesis processes.

Thalidomide as initial therapy for early-stage myeloma

Patients with early-stage myeloma are typically observed without therapy until symptomatic disease occurs. However, they are at high risk of progression to symptomatic myeloma, with a median time to progression of approximately 1-2 years. We report the final results of a phase II trial of thalidomide as initial therapy for early-stage multiple myeloma in an attempt to delay progression to symptomatic disease. In total, 31 patients with smoldering or indolent multiple myeloma were studied at the Mayo Clinic. Two patients were deemed ineligible because they were found to have received prior therapy for myeloma, and were excluded from analyses except for toxicity. Thalidomide was initiated at a starting dose of 200 mg/day. Patients were followed-up monthly for the first 6 months and every 3 months thereafter. Of the 29 eligible patients, 10 (34%) had a partial response to therapy with at least 50% or greater reduction in serum and urine monoclonal (M) protein. When minor responses (25-49% decrease in M protein) were included, the response rate was 66%. Three patients had progressive disease while on therapy. Kaplan-Meier estimates of progression-free survival are 80% at 1 year and 63% at 2 years. Major grade 3-4 toxicities included two patients with somnolence and one patient each with neuropathy, deep-vein thrombosis, hearing loss, weakness, sinus bradycardia, and edema. Thalidomide has significant activity in early-stage myeloma and has the potential to delay progression to symptomatic disease. This approach must be further tested in randomized trials.