Targeting vascular endothelial growth factor and angiogenesis for the treatment of colorectal cancer

A Study on the Mechanism of Herbal Drug FDY003 for Colorectal Cancer Treatment by Employing Network Pharmacology

Colorectal cancer (CRC) originates from the uncontrolled growth of epithelial cells in the colon or rectum. Annually, 1.9 million new CRC cases are being reported, causing 0.9 million deaths worldwide. The suppressive effects of the herbal prescription FDY003, a mixture of Cordyceps militaris, Lonicera japonica Thunberg, and Artemisia capillaris Thunberg, against CRC have previously been reported. Nonetheless, the multiple compound-multiple target mechanisms of FDY003 in CRC cells have not been fully elucidated. In this study, we used network pharmacology (NP) to analyze the polypharmacological mechanisms of action of FDY003 in CRC treatment. FDY003 promoted the suppression of viability of CRC cells and strengthened their sensitivity to anticancer drugs. The NP study enabled the investigation of 17 pharmaceutical compounds and 90 CRC-related genes that were targets of the compounds. The gene ontology terms enriched with the CRC-related target genes of FDY003 were those involved in the control of a variety of phenotypes of CRC cells, for instance, the decision of apoptosis and survival, growth, stress response, and chemical response of cells. In addition, the targeted genes of FDY003 were further enriched in various Kyoto Encyclopedia of Genes and Genomes pathways that coordinate crucial pathological processes of CRC; these are ErbB, focal adhesion, HIF-1, IL-17, MAPK, PD-L1/PD-1, PI3K-Akt, Ras, TNF, and VEGF pathways. The overall analysis results obtained from the NP methodology support the multiple-compound-multiple-target-multiple-pathway pharmacological features of FDY003 as a potential agent for CRC treatment.

Targeting the DNA Damage Response Pathway as a Novel Therapeutic Strategy in Colorectal Cancer

Simple Summary

Defective DNA damage response (DDR) is a hallmark of cancer leading to genomic instability. Up to 15–20% of colorectal cancers carry alterations in DDR. However, the role of DDR alterations as a prognostic factor and as a therapeutic target must be elucidated. To date, disappointing results have been obtained in different clinical trials mainly due to poor molecular selection of patients. Several challenges must be overcome before these compounds may have an impact on colorectal cancer. For instance, although some preclinical evidence showed the vulnerability of a subset of CRCs to PARP inhibitors, no specific clinical or molecular biomarkers have been validated to select patients. Moreover, different DDR alterations may not equally confer platinum sensitivity in CRC patients. Further efforts are needed in both preclinical and clinical settings to exploit DDR alterations as therapeutic targets and to eventually discover PARP or other DDR inhibitors (e.g., Wee1) with clinical benefit on colorectal cancer patients.

Abstract

Major advances have been made in CRC treatment in recent years, especially in molecularly driven therapies and immunotherapy. Despite this, a large number of advanced colorectal cancer patients do not benefit from these treatments and their prognosis remains poor. The landscape of DNA damage response (DDR) alterations is emerging as a novel target for treatment in different cancer types. PARP inhibitors have been approved for the treatment of ovarian, breast, pancreatic, and prostate cancers carrying deleterious BRCA1/2 pathogenic variants or homologous recombination repair (HRR) deficiency (HRD). Recent research reported on the emerging role of HRD in CRC and showed that alterations in these genes, either germline or somatic, are carried by up to 15–20% of CRCs. However, the role of HRD is still widely unknown, and few data about their clinical impact are available, especially in CRC patients. In this review, we report preclinical and clinical data currently available on DDR inhibitors in CRC. We also emphasize the predictive role of DDR mutations in response to platinum-based chemotherapy and the potential clinical role of DDR inhibitors. More preclinical and clinical trials are required to better understand the impact of DDR alterations in CRC patients and the therapeutic opportunities with novel DDR inhibitors.

Antitumor Effects of Carvacrol and Thymol: A Systematic Review

Background: It is estimated that one in five people worldwide faces a diagnosis of a malignant neoplasm during their lifetime. Carvacrol and its isomer, thymol, are natural compounds that act against several diseases, including cancer. Thus, this systematic review aimed to examine and synthesize the knowledge on the antitumor effects of carvacrol and thymol.

Methods: A systematic literature search was carried out in the PubMed, Web of Science, Scopus and Lilacs databases in April 2020 (updated in March 2021) based on the PRISMA 2020 guidelines. The following combination of health descriptors, MeSH terms and their synonyms were used: carvacrol, thymol, antitumor, antineoplastic, anticancer, cytotoxicity, apoptosis, cell proliferation, in vitro and in vivo. To assess the risk of bias in in vivo studies, the SYRCLE Risk of Bias tool was used, and for in vitro studies, a modified version was used.

Results: A total of 1,170 records were identified, with 77 meeting the established criteria. The studies were published between 2003 and 2021, with 69 being in vitro and 10 in vivo. Forty-three used carvacrol, 19 thymol, and 15 studies tested both monoterpenes. It was attested that carvacrol and thymol induced apoptosis, cytotoxicity, cell cycle arrest, antimetastatic activity, and also displayed different antiproliferative effects and inhibition of signaling pathways (MAPKs and PI3K/AKT/mTOR).

Conclusions: Carvacrol and thymol exhibited antitumor and antiproliferative activity through several signaling pathways. In vitro, carvacrol appears to be more potent than thymol. However, further in vivo studies with robust methodology are required to define a standard and safe dose, determine their toxic or side effects, and clarify its exact mechanisms of action.

This systematic review was registered in the PROSPERO database (CRD42020176736) and the protocol is available at https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=176736.

Metastatic Tumor-in-a-Dish, a Novel Multicellular Organoid to Study Lung Colonization and Predict Therapeutic Response

Metastasis is a major cause of cancer-related deaths. A dearth of preclinical models that recapitulate the metastatic microenvironment has impeded the development of therapeutic agents that are effective against metastatic disease. Because the majority of solid tumors metastasize to the lung, we developed a multicellular lung organoid that mimics the lung microenvironment with air sac-like structures and production of lung surfactant protein. We used these cultures, called primitive lung-in-a-dish (PLiD), to recreate metastatic disease using primary and established cancer cells. The metastatic tumor-in-a-dish (mTiD) cultures resemble the architecture of metastatic tumors in the lung, including angiogenesis. Pretreating PLiD with tumor exosomes enhanced cancer cell colonization. We next tested the response of primary and established cancer cells to current chemotherapeutic agents and an anti-VEGF antibody in mTiD against cancer cells in two-dimensional (2D) or 3D cultures. The response of primary patient-derived colon and ovarian tumor cells to therapy in mTiD cultures matched the response of the patient in the clinic, but not in 2D or single-cell-type 3D cultures. The sensitive mTiD cultures also produced significantly lower circulating markers for cancer similar to that seen in patients who responded to therapy. Thus, we have developed a novel method for lung colonization in vitro, a final stage in tumor metastasis. Moreover, the technique has significant utility in precision/personalized medicine, wherein this phenotypic screen can be coupled with current DNA pharmacogenetics to identify the ideal therapeutic agent, thereby increasing the probability of response to treatment while reducing unnecessary side effects. SIGNIFICANCE: A lung organoid that exhibits characteristics of a normal human lung is developed to study the biology of metastatic disease and therapeutic intervention.

4'-hydroxywogonin inhibits colorectal cancer angiogenesis by disrupting PI3K/AKT signaling

Angiogenesis is fundamental for solid tumor growth and metastasis, and anti-angiogenic therapy has been an important therapeutic option for cancer treatment. Colorectal cancer (CRC) represents the fourth leading cause of cancer-related death worldwide. The current studies were aimed at investigating the anti-angiogenic effects of the natural compound 4'-hydroxywogonin (4'-HW) on CRC-related angiogenesis. Human CRC cell line SW620 cells and normal human intestinal epithelial HIEC cells were cultured and treated with interleukin-6 to mimic the tumor inflammatory microenvironment. Our data showed that 4'-HW reduced the viability of SW620 cells in a concentration- and time-dependent manner. 4'-HW also suppressed the proliferation of SW620 cells, but had little effect on the viability of HIEC cells. Moreover, 4'-HW concentration-dependently decreased the mRNA and protein expression of vascular endothelial growth factor-A (VEGF-A), the predominant pro-angiogenic cytokine in tumor angiogenesis. Subsequently, 4'-HW concentration-dependently inhibited the phosphorylation of phosphatidylinositol 3-kinase (PI3K) and AKT. PI3K inhibitor wortmannin, similar to 4'-HW, significantly downregulated the VEGF-A expression in SW620 cells, and combination of wortmannin and 4'-HW produced more significant effects. Finally, human umbilical vein endothelial cells (HUVECs) incubated with the conditioned medium of 4'-HW-treated SW620 cells exhibited impaired angiogenic capacity at Matrigel. Incubation with the neutralizing antibody against VEGF-Aalone also suppressed the angiogenic properties of HUVECs in vitro. Collectively, 4'-HW decreased the viability and reduced angiogenesis in CRC, which was associated with downregulation of VEGF-A expression by disrupting the PI3K/AKT pathway. Our discoveries suggested 4'-HW as a promising anticancer agent against CRC targeting angiogenesis.

Antiangiogenic therapy in the management of breast cancer

An improved understanding of the important role of angiogenesis in tumor biology has led to development of different antiangiogenic therapies. Numerous clinical studies for several antiangiogenic agents have recently been conducted in breast cancer patients and have shown clinically significant improvement in outcomes. This review focuses on current progress in the field of antiangiogenic therapy in the management of breast cancer, also highlighting issues regarding future therapeutic development that result in the greatest clinical benefits and minimizing the adverse effects.

Correlation of ADCC activity with cytokine release induced by the stably expressed, glyco-engineered humanized Lewis Y-specific monoclonal antibody MB314

A major limitation to the application of therapeutic monoclonal antibodies (mAbs) is their reduced in vivo efficacy compared with the high efficacy measured in vitro. Effector functions such as antibody-dependent cell-mediated cytotoxicity (ADCC) are dramatically reduced in vivo by the presence of high amounts of endogenous IgG in the serum. Recent studies have shown that modification of the glycosylation moieties attached to the Fc part of the mAb can enhance binding affinity to FcγRIIIα receptors on natural killer cells and thus may counteract the reduced in vivo efficacy. In the present study, a humanized IgG1/κ monoclonal antibody recognizing the tumor-associated carbohydrate antigen Lewis Y was stably produced in a moss expression system that allows glyco-engineering. The glyco-modified mAb (designated MB314) showed a highly homogeneous N-glycosylation pattern lacking core-fucose. A side-by-side comparison to its parental counterpart produced in conventional mammalian cell-culture (MB311, formerly known as IGN311) by fluorescence-activated cell sorting analysis confirmed that the target specificity of MB314 is similar to that of MB311. In contrast, ADCC effector function of MB314 was increased up to 40-fold whereas complement dependent cytotoxicity activity was decreased 5-fold. Notably, a release of immunostimulatory cytokines, including interferon γ, monocyte chemotactic protein-1 (MCP-1), interleukin-6 and tumor necrosis factor (TNF) was particularly induced with the glyco-modified antibody. TNF release was associated with CD14 (+) cells, indicating activation of monocytes.

Attenuated expression of HRH4 in colorectal carcinomas: a potential influence on tumor growth and progression

BACKGROUND

Earlier studies have reported the production of histamine in colorectal cancers (CRCs). The effect of histamine is largely determined locally by the histamine receptor expression pattern. Recent evidence suggests that the expression level of histamine receptor H4 (HRH4) is abnormal in colorectal cancer tissues. However, the role of HRH4 in CRC progression and its clinical relevance is not well understood. The aim of this study is to evaluate the clinical and molecular phenotypes of colorectal tumors with abnormal HRH4 expression.

METHODS

Immunoblotting, real-time PCR, immunofluorescence and immunohistochemistry assays were adopted to examine HRH4 expression in case-matched CRC samples (n = 107) and adjacent normal tissues (ANTs). To assess the functions of HRH4 in CRC cells, we established stable HRH4-transfected colorectal cells and examined cell proliferation, colony formation, cell cycle and apoptosis in these cells.

RESULTS

The protein levels of HRH4 were reduced in most of the human CRC samples regardless of grade or Dukes classification. mRNA levels of HRH4 were also reduced in both early-stage and advanced CRC samples. In vitro studies showed that HRH4 over-expression caused growth arrest and induced expression of cell cycle proteins in CRC cells upon exposure to histamine through a cAMP -dependent pathway. Furthermore, HRH4 stimulation promoted the 5-Fu-induced cell apoptosis in HRH4-positive colorectal cells.

CONCLUSION

The results from the current study supported previous findings of HRH4 abnormalities in CRCs. Expression levels of HRH4 could influence the histamine-mediated growth regulation in CRC cells. These findings suggested a potential role of abnormal HRH4 expression in the progression of CRCs and provided some new clues for the application of HRH4-specific agonist or antagonist in the molecular therapy of CRCs.

Tumor-derived VEGF modulates hematopoiesis

VEGF-induced angiogenesis significantly contributes to tumor growth, invasion and metastasis. However, little is known about its hematopoietic activity during malignant development and progression. Here we show that in a mouse tumor model, tumor-derived VEGF acts as an endocrine-like hormone to induce extramedullary hematopoiesis by targeting distal organs in the host. In tumor-bearing mice, circulating VEGF induced hepatomegaly and splenomegaly owing to vessel dilation, tortuosity and activation of hematopoiesis. Furthermore, VEGFR1 and VEGFR2 were primarily localized in blood vessels rather than hepatocytes or splenocytes, demonstrating that alteration of angiogenic profiles modulates hematopoiesis in these organs. Stimulation of extramedullary hematopoiesis sheds new light on complex biological functions of VEGF and significantly increases our understanding of molecular mechanisms underlying VEGF-induced tumor growth.

Update on clinical data combining capecitabine with targeted agents in newly diagnosed colorectal cancer

Colorectal cancer (CRC) is a worldwide public health problem, with nearly 800,000 new cases diagnosed each year, resulting in approximately 500,000 deaths. When advanced metastatic disease is diagnosed, CRC is associated with a poor prognosis, and 5-year survival rates are in the range of 5%-8%. Chemotherapy has been the mainstay approach for patients with advanced CRC. For nearly 40 years, the main drug used for this disease was the fluoropyrimidine 5-fluorouracil (5-FU). Significant advances have been made in chemotherapy treatment options for patients with metastatic disease, such that improvements in 2-year survival are now being reported with median survival rates of 21 months to 24 months. Over the past 10 years, 3 new cytotoxic chemotherapy agents have been approved by the FDA for metastatic CRC. These compounds include the topoisomerase I inhibitor irinotecan, the third-generation platinum analogue oxaliplatin, and the oral fluoropyrimidine capecitabine. Since 2004, 3 novel biologic agents have been approved by the FDA, and they include the anti-epidermal growth factor receptor antibodies cetuximab and panitumumab and the anti-vascular endothelial growth factor bevacizumab. The oral fluoropyrimidine capecitabine has been effectively and safely combined with irinotecan (CAPIRI) and/or oxaliplatin (CAPOX). Three randomized phase III studies have now shown that CAPOX is equivalent to FOLFOX (5-FU/leucovorin/oxaliplatin)-based regimens. Significant interest has centered around combining capecitabine-based cytotoxic regimens with the biologic agents, and specifically, bevacizumab and cetuximab. This review will update the current status of these capecitabine-based combination regimens.

Influence of varying doses of granulocyte-macrophage colony-stimulating factor on pharmacokinetics and antibody-dependent cellular cytotoxicity

Recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) is used in immunotherapy for correction of neutropoenia. The optimal dose for activation of immune functions and the pharmacokinetics following repeated administrations is less analysed in depth. In this study, the pharmacokinetics and the effects on haematological functions and antibody-dependent cellular cytotoxicity (ADCC) were analysed in 50 patients with metastatic colorectal carcinoma receiving monoclonal antibody based therapy in combination with Escherichia coli-derived GM-CSF (molgramostim) administered s.c. once daily for 10 days every month over a period of 4 months. Thirty-three patients received a GM-CSF dose of 200-250 microg/m(2)/day. Seventeen patients received GM-CSF doses varying between 65 and 325 microg/m(2)/day in the different treatment cycles. Serum GM-CSF concentration was measured (ELISA) before and 3-4 h after (peak serum concentration) GM-CSF administration days 1, 5 and 10. Prior to therapy, GM-CSF was not detectable in serum. Following repeated daily administrations, the peak serum concentration of GM-CSF gradually decreased on days 5 and 10 compared to day 1 (P < 0.05). During a 10-day treatment cycle, the total number of leukocytes, neutrophils, eosinophils, monocytes and lymphocytes increased. A dose-dependent increment in total white blood cell count and neutrophils was observed. The total numbers of GM-CSF receptor (alpha-subunit) expressing cells (granulocytes and monocytes) increased significantly during treatment while a transient decline in expression intensity was observed at day 5, suggesting a receptor-mediated removal of GM-CSF as a mechanism for the elimination of GM-CSF from circulation. ADCC of peripheral mononuclear cells was decreased at day 10 compared to baseline. An inverse correlation between the dose and ADCC was noted. The data might indicate that high doses of GM-CSF may have a negative impact on ADCC.

Monoclonal antibodies as targeted therapy in hematologic malignancies in older adults

BACKGROUND

Biological agents are proving to be increasingly useful and exciting additions to the antineoplastic armamentarium, but many clinicians are unfamiliar with the properties of these types of agents.

OBJECTIVES

This review focuses on monoclonal antibodies (MAbs) that are used in the treatment of hematologic malignancies. Our goal was to provide the reader with information on trials that led to US Food and Drug Administration (FDA) approval of commonly used MAbs in hematologic malignancies, including their mechanisms of action and pharmacokinetics, with specific emphasis on use in elderly patients; we also present data on toxicities and precautions to be aware of when administering these drugs.

METHODS

Materials for this review were gathered based on a computerized literature search (English-language articles only) using the PubMed database covering the period January 1998 to December 2005. Search terms used included the following: elderly, monoclonal antibodies, and neoplasms.

RESULTS

Alemtuzumab is a recombinant DNA-derived, humanized MAb directed against the CD52 B-cell antigen. It is indicated for the treatment of B-cell chronic lymphocytic leukemia (CLL) in patients who have been treated with alkylating agents and who have failed to respond to fludarabine therapy. Gemtuzumab ozogamicin is an MAb conjugated with a cytotoxic antitumor antibiotic, calicheamicin. It has been approved for use in patients with CD33-positive acute myeloid leukemia (AML) in first relapse who are aged > or =60 years and who are not considered candidates for other cytotoxic chemotherapy. Rituximab, one of the first MAbs approved by the FDA for use in human cancers, is an antibody directed against the CD20 antigen found on the surface of normal and malignant B lymphocytes. It is extensively used in the treatment of B-cell malignancies, such as CLL, and non-Hodgkin's lymphomas (NHLs), such as follicular lymphoma and diffuse large B-cell lymphoma.

CONCLUSIONS

It is noteworthy that while there have been a number of studies using these agents in the younger population, there continues to be a paucity of clinical trials targeting the elderly patient in particular; this continues to be an area of research interest. More clinical studies of these agents--conducted specifically in elderly patients with CLL, NHL, AML, and other hematologic malignancies--are needed.

Antiangiogenic effect of TW37, a small-molecule inhibitor of Bcl-2

Bcl-2 is an antiapoptotic protein that is up-regulated in several tumor types, and its expression levels have strong correlation to development of resistance to therapy and poor prognosis. We have shown recently that Bcl-2 also functions as a proangiogenic signaling molecule that activates a nuclear factor-kappaB-mediated pathway resulting in up-regulation of the angiogenic chemokines CXCL1 and CXCL8 by neovascular endothelial cells. Here, we evaluate the antiangiogenic effect of the novel small-molecule inhibitor of Bcl-2 (TW37) developed using a structure-based design strategy. We observed that TW37 has an IC(50) of 1.8 mumol/L for endothelial cells but showed no cytotoxic effects for fibroblasts at concentrations up to 50 mumol/L. The mechanism of TW37-induced endothelial cell death was apoptosis, in a process mediated by mitochondrial depolarization and activation of caspase-9 and caspase-3. The effect of TW37 on endothelial cell apoptosis was not prevented by coexposure to the growth factor milieu secreted by tumor cells. Inhibition of the angiogenic potential of endothelial cells (i.e., migration and capillary sprouting assays) and expression of the angiogenic chemokines CXCL1 and CXCL8 were accomplished at subapoptotic TW37 concentrations (0.005-0.05 micromol/L). Notably, administration of TW37 i.v. resulted in a decrease in the density of functional human microvessels in the severe combined immunodeficient mouse model of human angiogenesis. In conclusion, we describe functionally separate proapoptotic and antiangiogenic mechanisms for a small-molecule inhibitor of Bcl-2 and show the potential for Bcl-2 inhibition as a target for antiangiogenic therapy.

From Nutraceuticals to Pharmaceuticals to Nanopharmaceuticals: A Case Study in Angiogenesis Modulation During Oxidative Stress

This report reviews the potential applications of nanotechnology in various therapeutics and diagnostics areas with special emphasis on key frontiers in angiogenesis modulation using naturally driven drug targets including compounds that modulate oxidative stress and inflammatory pathways for the potential treatment of vascular, cancer, inflammatory, and ocular disorders. Recent advances of the nanotechnology mediated gene delivery are also described in this paper.

Effect of timing of surgery on survival after preoperative hyperfractionated accelerated radiotherapy (HART) for locally advanced rectal cancer (LARC): is it a matter of days?

We intend to analyse retrospectively whether the time interval ("gap duration" = GD) between preoperative radiotherapy and surgery in locally advanced rectal cancer (LARC) has an impact on overall survival (OS), cancer specific survival (CSS), disease free survival (DFS) and local control (LC). Two hundred seventy nine patients with LARC were entered in Trial 93-01 (hyperfractionated accelerated radiotherapy 41.6 Gy/26 Fx BID) shortly followed by surgery. From these 250 patients are fully assessable. The median GD of 5 days was used as a discriminator. The median follow-up for all patients was 39 months. GD > 5 days was a significant discriminator for actuarial 5-years OS (69% vs 47%, p = 0.002), CSS (82% vs 57%, p = 0.0007), DFS (62% vs 41%, p = 0.0003) but not for LC (93% vs 90%, p = non-significant). In multivariate analysis, the following factors independently predict outcome; for OS: age, GD, circumferential margin (CM) and nodal stage (ypN); for CSS: GD, ypN and vascular invasion (VI); for DFS: CEA, distance to anal verge, GD, ypN and VI; for LC: CM only. Gap duration predicts survival outcome but not local control. The patients submitted to surgery after a median delay of more than 5 days had a significantly better outcome.

Recent developments in colorectal cancer treatment by monoclonal antibodies

A growing understanding of the molecular mechanisms involved in cancer biology and continuous refinement of available technologies for drug discovery have prompted the development of new therapeutic tools targeting specific cancer-associated molecular pathways. Among these so-called biological therapies, monoclonal antibodies have now reached the time of clinical application. Besides initial development of the murine antibody edrecolomab, the impact of monoclonal antibodies on cancer therapy has recently been clearly demonstrated in colorectal cancer by targeting two major pathways critical to tumourigenesis: the epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) signalling pathways. These antibodies showed significant clinical activity in advanced colorectal cancer, especially when combined with chemotherapy. This paper reviews the status of the monoclonal chimeric antibody cetuximab (Erbitux) and other anti-EGFR antibodies, and of bevacizumab (Avastin; an anti-VEGF humanised monoclonal antibody), in colorectal cancer treatment.

Recent advances in targeted therapies for colorectal cancer

BACKGROUND

Recent advances in the molecular biology and genetics of colorectal cancer have led to the identification of potential therapeutic targets such as epidermal growth factor receptor, vascular endothelial growth factor and endothelial receptors.

OBJECTIVE

This review will examine the major therapeutic advances along with the preclinical basis justifying their combination with conventional therapeutic tools. This review will also critically consider current possibilities offered to identify responding patients.

DATA SOURCES

Preclinical and primary clinical trial results published in peer-review journals. The authors examined the relevance and subsequent inclusion of the data.

CONCLUSIONS

Cetuximab and bevacizumab provide new benefits in terms of the response rate and survival. There remain, however, important questions concerning, for instance, optimal combinations between conventional cytotoxic agents and targeted therapies and also between targeted drugs themselves. These new targeted treatments are costly and in this context the question of the identification of the right drug for the right patient is particularly relevant. Adequate tools in predicting the efficacy of targeted treatments are still needed.

Metastatic colorectal cancer

Metastatic colorectal cancer remains a public-health issue on a global scale. With development of a new generation of cytotoxic agents, survival has improved for patients with metastatic disease. How to maximize the benefit of chemotherapy with acceptable toxicity remains incompletely answered. Hepatic resection can provide a significant hope for long term survival, and a subset of patients might benefit from perioperative approaches. More recently, specific molecular processes have been targeted for therapeutic interventions, and encouraging results have been achieved using inhibitors of the Epidermal Growth Factor Receptor and the Vascular Endothelial Growth Factor.

Potent neutralization of VEGF biological activities with a fully human antibody Fab fragment directed against VEGF receptor 2

Compelling evidence suggest that vascular endothelial growth factor (VEGF) and its receptors, especially receptor 2 (VEGFR2, or kinase insert domain-containing receptor, KDR), play a critical role in angiogenesis under both physiological and pathological conditions, including cancer and angiogenic retinopathies such as age-related macular degeneration (AMD). To this end, inhibition of angiogenesis with antagonists to either VEGF or KDR has yielded significant therapeutic efficacy both in preclinical studies in animal models and in clinical trials in patients with cancer and AMD. We previously reported the identification of a high affinity, fully human anti-KDR antibody fragment, 1121B Fab, through a highly stringent affinity maturation process with a Fab originally isolated from a naïve human antibody phage display library. In this study, we demonstrate that 1121B Fab is able to strongly block KDR/VEGF interaction, resulting in potent inhibition of an array of biological activities of VEGF, including activation of the receptor and its signaling pathway, intracellular calcium mobilization, and migration and proliferation of endothelial cells. Taken together, our data lend strong support to the further development of 1121B Fab fragment as an anti-angiogenesis agent in both cancer and angiogenic retinopathies.

Cancer immunotherapy

Cancer is the second leading cause of death in the industrialized world. Most cancer patients are treated by a combination of surgery, radiation and/or chemotherapy. Whereas the primary tumor can, in most cases, be efficiently treated by a combination of these standard therapies, preventing the metastatic spread of the disease through disseminated tumor cells is often not effective. The eradication of disseminated tumor cells present in the blood circulation and micro-metastases in distant organs therefore represents another promising approach in cancer immunotherapy. Main strategies of cancer immunotherapy aim at exploiting the therapeutic potential of tumor-specific antibodies and cellular immune effector mechanisms. Whereas passive antibody therapy relies on the repeated application of large quantities of tumor antigen-specific antibodies, active immunotherapy aims at the generation of a tumor-specific immune response combining both humoral and cytotoxic T cell effector mechanisms by the host's immune system following vaccination. In the first part of this review, concurrent developments in active and passive cancer immunotherapy are discussed. In the second part, the various approaches for the production of optimized monoclonal antibodies used for anti-cancer vaccination are summarized.

Targeted Therapies: A Nursing Perspective

OBJECTIVES

To review the development of targeted therapies and the biology of relevant therapeutic targets. To analyze the relevance of targeted agents as part of current clinical practice.

DATA SOURCES

Research articles.

CONCLUSION

Several targeted agents are now available for clinical use. Their mechanisms of action are more specific against tumor cells than traditional cytotoxics. Monotherapy regimens based on targeted agents tend to be better tolerated than chemotherapy, and most combination regimens with targeted agents have proven feasible. Their availability has greatly expanded cancer treatment options, especially for chemorefractory patients.

IMPLICATIONS FOR NURSING PRACTICE

Nurses involved in the care of patients with cancer can benefit from an increased understanding of targeted therapies, including their mechanisms of action, their efficacy profile, as well as prophylaxis and management of adverse events and administration procedures.

EWS–ETS oncoproteins: The linchpins of Ewing tumors

Ewing tumors, which comprise Ewing's sarcoma and peripheral primitive neuroectodermal tumors, are highly aggressive and mostly affect children and adolescents. Their molecular signature is a chromosomal translocation leading to the generation of EWS-ETS (or very rarely FUS-ETS) fusion proteins that are capable of transforming cells. These oncoproteins act as aberrant transcription factors due to the fusion of an ETS DNA binding domain to a highly potent EWS (or FUS) transactivation domain. Accordingly, many EWS-ETS target genes have been identified whose dysregulation could contribute to the development of tumor formation. Furthermore, EWS-ETS oncoproteins may impact on RNA splicing or affect other proteins through disturbing their ability to form functional complexes. The molecular knowledge gained so far from studying EWS-ETS oncoproteins has not only broadened our understanding of Ewing tumors but also improved the diagnosis of these highly undifferentiated tumors. In addition, several potential prognostic markers have been uncovered and novel therapies are suggested that may improve the still dismal survival rate of Ewing tumor patients.

Angiogenesis in gliomas: imaging and experimental therapeutics

Much of the interest in angiogenesis and hypoxia has led to investigating diagnostic imaging methodologies and developing efficacious agents against angiogenesis in gliomas. In many ways, because of the cytostatic effects of these agents on tumor growth and tumor-associated endothelial cells, the effects of therapy are not immediately evident. Hence finding clinically applicable imaging tools and pathologic surrogate markers is an important step in translating glioma biology to therapeutics. There are a variety of strategies in the approach to experimental therapeutics that target the hypoxia-inducible factor pathway, the endogenous antiangiogenic and proangiogenic factors and their receptors, adhesion molecules, matrix proteases and cytokines, and the existing vasculature. We discuss the rationale for antiangiogenesis as a treatment strategy, the preclinical and clinical assessment of antiangiogenic interventions and finally focus on the various treatment strategies, including combining antiangiogenic drugs with radiation and chemotherapy.