Effects of palifermin on antitumor activity of chemotherapeutic and biological agents in human head and neck and colorectal carcinoma xenograft models

Synergistic therapeutic strategies and engineered nanoparticles for anti-vascular endothelial growth factor therapy in cancer

Angiogenesis is one of the defining characteristics of cancer. Vascular endothelial growth factor (VEGF) is crucial for the development of angiogenesis. A growing interest in cancer therapy is being caused by the widespread use of antiangiogenic drugs in treating several types of human cancer. However, this therapeutic approach can worsen resistance, invasion, and overall survival. As we proceed, refining combination strategies and addressing the constraint of targeted treatments are paramount. Therefore, major challenges in using novel combinations of antiangiogenic agents with cytotoxic treatments are currently focused on illustrating the potential of synergistic therapeutic strategies, alongside advancements in nanomedicine and gene therapy, present opportunities for more precise interference with angiogenesis pathways and tumor environments. Nanoparticles have the potential to regulate several crucial activities and improve several drug limitations such as lack of selectivity, non-targeted cytotoxicity, insufficient drug delivery at tumor sites, and multi-drug resistance based on their unique features. The goal of this updated review is to illustrate the enormous potential of novel synergistic therapeutic strategies and the targeted nanoparticles as an alternate strategy for t treating a variety of tumors employing antiangiogenic therapy.

Keratinocyte growth factor in focus: A comprehensive review from structural and functional aspects to therapeutic applications of palifermin

Palifermin (Kepivance™) is the first therapeutic approved by the Food and Drug Administration for preventing and managing the oral mucositis provoked by myelotoxic and mucotoxic therapies. Palifermin is a recombinant protein generated from human keratinocyte growth factor (KGF) and imitates the function of endogenous KGF. KGF is an epithelial mitogen involved in various biological processes which belongs to the FGF family. KGF possesses a high level of receptor specificity and plays an important role in tissue repair and maintaining of the mucosal barrier integrity. Based on these unique features, palifermin was developed to enhance the growth of damaged epithelial tissues. Administration of palifermin has shown success in the reduction of toxicities of chemotherapy and radiotherapy, and improvement of the patient's quality of life. Notwithstanding all merits, the clinical application of palifermin is limited owing to its instability and production challenges. Hence, a growing number of ongoing researches are designed to deal with these problems and enhance the physicochemical and pharmaceutical properties of palifermin. In the current review, we discuss KGF structure and function, potential therapeutic applications of palifermin, as well as the latest progress in the production of recombinant human KGF and its challenges ahead.

A Prospective Cohort Study Comparing Long-Term Outcomes with and without Palifermin in Patients Receiving Hematopoietic Cell Transplantation for Hematologic Malignancies

The incidence of debilitating oral mucositis (OM) can be as high as 99% after myeloablative conditioning regimens preparing patients with hematologic malignancies for hematopoietic cell transplantation (HCT). Palifermin (KGF) is a recombinant human keratinocyte growth factor that reduces the incidence and duration of severe OM. The long-term safety of KGF has not been well established, however. In this long-term prospective matched-cohort study, patients who received KGF (cases) and underwent autologous or allogeneic HCT for hematologic malignancies between 2006 and 2013 were matched 1:1 to patients who did not receive KGF (controls). The primary outcome was overall survival (OS). Other outcomes were disease relapse, new malignancies, pancreatitis, renal failure requiring dialysis, pulmonary complications, cataract surgery, and acute and chronic graft-versus-host disease (GVHD). The analysis population comprised 2191 matched pairs with a wide range of diseases and donor types that received diverse conditioning and GVHD preventive regimens, representing contemporary practice patterns. The median duration of follow-up was 8 years (range, 1 to 12.5 years). In multivariate analyses, the probabilities of OS (relative risk [RR], 1.01; 95% confidence interval [CI], 0.91 to 1.12), relapse (RR, 1.06; 95% CI, 0.94 to 1.18), new malignancies (RR, 0.89; 95% CI, 0.67 to 1.18), and cataract surgery (RR, 1.05; 95% CI, 0.74 to 1.50) were not statistically significantly different between cases and controls. In univariate analyses, no increased risks were observed for renal failure requiring dialysis, pancreatitis, acute GVHD, chronic GVHD, interstitial pneumonitis/acute respiratory distress syndrome/idiopathic pneumonia syndrome, or bronchiolitis obliterans/cryptogenic organizing pneumonia/bronchiolitis obliterans organizing pneumonia among cases compared with controls. This long-term prospective safety cohort study demonstrates that the KGF group had no increased risk of overall mortality, relapse, new malignancies, or any other key outcome. The broad inclusion criteria allow the results to be generalized to contemporary practice for patients with a wide range of diseases and receiving a wide range of HCT conditioning regimens and graft sources from diverse donor types.

[Master regulators associated with poor prognosis in glioblastoma multiforme]

Glioblastoma multiforme (GBM) is a highly malignant brain tumor with average survival time of 15 months. Less than 2% of the patients survive beyond 36 months. To understand the molecular mechanism responsible for poor prognosis, we analyzed GBM samples of TCGA microarray (n=560) data. We have identified 720 genes that have a significant impact upon survival based on univariate cox regression. We applied the Genome Enhancer pipeline to analyze potential mechanisms of regulation of activity of these genes and to build gene regulatory networks. We identified 12 transcription factors enriched in the promoters of these genes including the key molecule of GBM - STAT3. We found that STAT3 had significant differential expression across extreme survivor groups (short-term survivors- survival 36 months) and also had a significant impact on survival. In the next step, we identified master regulators in the signal transduction network that regulate the activity of these transcription factors. Master regulators are filtered based on their differential expression across extreme survivors groups and impact on survival. This work validates our earlier report on master regulators IGFBP2, PDGFA, OSMR, and AEBP1 driving short survival. Additionally, we propose CD14, CD44, DUSP6, GRB10, IL1RAP, FGFR3, and POSTN as master regulators driving poor survival. These master regulators are proposed as promising therapeutic targets to counter poor prognosis in GBM. Finally, the algorithm has prioritized several drugs for the further study as potential remedies to conquer the aggressive forms of GBM and to extend survival of the patients.

GM-1111 reduces radiation-induced oral mucositis in mice by targeting pattern recognition receptor-mediated inflammatory signaling

PURPOSE

Oral mucositis (OM) is a common, painful side effect of radiation therapy used for the treatment of head and neck cancer (HNC). Activation of the innate immune system upon irradiation has been identified as a key precipitating event of OM. To better understand OM's pathogenesis, we studied pattern recognition receptors (PRRs) and their downstream pro-inflammatory cytokines in a mouse model of radiation-induced OM. We also tested therapeutic efficacy of GM-1111 that targets innate immune system to reduce radiation-induced OM.

METHODS AND MATERIALS

The pathogenesis of OM was studied in a single X-ray induced mouse model. The severity of OM was measured by visual and microscopical examinations. The irradiation-induced changes of PRRs and their downstream effector cytokine gene expression levels were determined. The efficacy of GM-1111 to reduce OM was tested in single and fractionated irradiation mouse models. The impact of the drug on tumor response to radiation therapy was also tested in a mouse model of human HNC.

RESULTS

Radiation-induced tissue ulcerations were radiation-dosage and -time dependent. The lesions showed selective increases in PRR and pro-inflammatory cytokine gene expression levels. Once daily administration of GM-1111 (≥30 mg/kg, s.c.) significantly reduced the severity and the incidence of OM. The drug had little effect on PRRs but significantly inhibited downstream pro-inflammatory cytokine genes. GM-1111 did not interfere radiation therapy to induce HNC SCC-25 tumor regression. Instead, we observed significant drug-induced tumor regression.

CONCLUSIONS

Radiation induces tissue damages. The increased expression levels of PRRs and their downstream pro-inflammatory cytokine genes in the damaged tissues suggest their important contribution to the pathogenesis of OM. Drug GM-1111 that targets these innate immune molecules may be a potential drug candidate as an intervention for OM.

Keratinocyte Growth Factor-1 Protects Radioiodine-Induced Salivary Gland Dysfunction in Mice

BACKGROUND

Most patients with thyroid cancer suffer from salivary gland (SG) dysfunctions after radioiodine (RI) therapy. We investigated the effects of keratinocyte growth factor (KGF)-1 on RI-induced SG dysfunction in an animal model.

METHODS

Six C57BL/6 mice were assigned to each of the following groups: treatment naïve control group, RI group, and RI+KGF-1 group. Body and SG weights, salivary flow rates, salivary lag times and changes in 99mTc pertechnetate uptake and excretion were measured, and histologic changes were noted. Amylase activities and epidermal growth factor (EGF) concentrations in saliva were also measured. In addition, TUNEL assays were performed and apoptosis-related protein expressions were assessed.

RESULTS

RI-induced reductions in salivary flow rates and increases in salivary lag times observed in the RI group were not observed in RI+KGF-1 group. Mice in RI group had higher HIF1a levels than controls, but HIF1a levels in RI+KGF-1 group were similar to those in control group. Furthermore, mice in RI+KGF-1 group had more mucin stained acini and decreased periductal fibrosis than mice in RI group, and tissue remodeling of many salivary epithelial cells (AQP5) and endothelial cells (CD31) were observed in RI+KGF-1 group. Amylase activity and expression in saliva were greater in RI+KGF-1 group than in RI group, and fewer apoptotic cells were observed in RI+KGF-1 group. Furthermore, BCLxl (anti-apoptotic) expression was higher, and Bax (pro-apoptotic) expression was lower in RI+KGF-1 group than in RI group.

CONCLUSIONS

Local delivery of KGF-1 might prevent RI-induced SG damage by reducing apoptosis.

Hair eruption initiates and commensal skin microbiota aggravate adverse events of anti-EGFR therapy

Epidermal growth factor receptor (EGFR)-targeted anticancer therapy induces stigmatizing skin toxicities affecting patients' quality of life and therapy adherence. The lack of mechanistic details underlying these adverse events hampers their management. We found that EGFR/ERK signaling is required in LRIG1-positive stem cells during de novo hair eruption to secure barrier integrity and prevent the invasion of commensal microbiota and inflammatory skin disease. EGFR-deficient epidermis is permissive for microbiota outgrowth and displays an atopic-like TH2-dominated signature. The opening of the follicular ostia during hair eruption allows invasion of commensal microbiota into the hair follicle, initiating an additional TH1 and TH17 response culminating in chronic folliculitis. Restoration of epidermal ERK signaling via prophylactic FGF7 treatment or transgenic SOS expression rescues the barrier defect in the absence of EGFR, highlighting a therapeutic anchor point. These data reveal that commensal skin microbiota provoke atopic-like inflammatory skin diseases by invading into the follicular opening of erupting hair.

Effect of photobiomodulation on the severity of oral mucositis and molecular changes in head and neck cancer patients undergoing radiotherapy: a study protocol for a cost-effectiveness randomized clinical trial

Background

Oral mucositis (OM) is the most frequent and debilitating acute side effect associated with head and neck cancer (HNC) treatment. When present, severe OM negatively impacts the quality of life of patients undergoing HNC treatment. Photobiomodulation is a well-consolidated and effective therapy for the treatment and prevention of severe OM, and is associated with a cost reduction of the cancer treatment. Although an increase in the quality of life and a reduction in the severity of OM are well described, there is no study on cost-effectiveness for this approach considering the quality of life as a primary outcome. In addition, little is known about the photobiomodulation effects on salivary inflammatory mediators. Thus, this study aimed to assess the cost-effectiveness of the photobiomodulation therapy for the prevention and control of severe OM and its influence on the salivary inflammatory mediators.

Methods/design

This randomized, double-blind clinical trial will include 50 HNC patients undergoing radiotherapy or chemoradiotherapy. The participants will be randomized into two groups: intervention group (photobiomodulation) and control group (preventive oral care protocol). OM (clinical assessment), saliva (assessment of collected samples) and quality of life (Oral Health Impact Profile-14 and Patient-Reported Oral Mucositis Symptoms questionnaires) will be assessed at the 1st, 7th, 14th, 21st and 30th radiotherapy sessions. Oxidative stress and inflammatory cytokine levels will be measured in the saliva samples of all participants. The costs are identified, measured and evaluated considering the radiotherapy time interval. The incremental cost-effectiveness ratio will be estimated. The study will be conducted according to the Brazilian public health system perspective.

Discussion

Photobiomodulation is an effective therapy that reduces the cost associated with OM treatment. However, little is known about its cost-effectiveness, mainly when quality of life is the effectiveness measure. Additionally, this therapy is not supported by the Brazilian public health system. Therefore, this study widens the knowledge about the safety of and strengthens evidence for the use of photobiomodulation therapy, providing information for public policy-makers and also for dental care professionals. This study is strongly encouraged due to its clinical relevance and the possibility of incorporating new technology into public health systems.

Trial registration

Brazilian Registry of Clinical Trials—ReBEC, RBR-5h4y4n. Registered on 13 June 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3196-8) contains supplementary material, which is available to authorized users.

Radioprotective effects of Keratinocyte Growth Factor-1 against irradiation-induced salivary gland hypofunction

Irradiation can cause salivary gland hypofunction, with hyposalivation producing discomfort, health risks, and reducing function in daily life. Despite increasing translational research interest in radioprotection, there are no satisfactory treatments available. Keratinocyte growth factor-1 stimulates proliferation of salivary epithelial cells or salivary stem/progenitor cells. However, the exact mechanism of its radioprotection against radiation-induced salivary hypofunction is not fully elucidated. Our results reveal that the radioprotective effects of keratinocyte growth factor-1 involved alleviation of growth inhibition and anti-apoptotic cell death of human parotid epithelial cells. Furthermore, keratinocyte growth factor-1 protected human parotid epithelial cells through the phosphoinositide 3-kinase - protein kinase B (Akt) pathway and inhibition of p53-mediated apoptosis through activation of mouse double minute 2. Local delivery of keratinocyte growth factor-1 into the irradiated salivary glands could protect radiation-induced salivary cell damages, suppress p53-mediated apoptosis and prevent salivary hypofunction in vivo. This suggests that keratinocyte growth factor-1 is a promising candidate to prevent radiation-induced salivary hypofunction and raise rational development keratinocyte growth factor-1 local delivery system.

Licochalcone-A induces intrinsic and extrinsic apoptosis via ERK1/2 and p38 phosphorylation-mediated TRAIL expression in head and neck squamous carcinoma FaDu cells

We investigated Licochalcone-A (Lico-A)-induced apoptosis and the pathway underlying its activity in a pharyngeal squamous carcinoma FaDu cell line. Lico-A purified from root of Glycyrrhiza inflata had cytotoxic effects, significantly increasing cell death in FaDu cells. Using a cell viability assay, we determined that the IC50 value of Lico-A in FaDu cells was approximately 100 µM. Chromatin condensation was observed in FaDu cells treated with Lico-A for 24 h. Consistent with this finding, the number of apoptotic cells increased in a time-dependent manner when FaDu cells were treated with Lico-A. TRAIL was significantly up-regulated in Lico-A-treated FaDu cells in a dose-dependent manner. Apoptotic factors such as caspases and PARP were subsequently activated in a caspase-dependent manner. In addition, levels of pro-apoptotic factors increased significantly in response to Lico-A treatment, while levels of anti-apoptotic factors decreased. Lico-A-induced TRAIL expression was mediated in part by a MAPK signaling pathway involving ERK1/2 and p38. In xenograft mouse model, Lico-A treatment effectively suppressed the growth of FaDu cell xenografts by activating caspase-3, without affecting the body weight of mice. Taken together, these data suggest that Lico-A has potential chemopreventive effects and should therefore be developed as a chemotherapeutic agent for pharyngeal squamous carcinoma.

Review of preclinical studies on treatment of mucositis and associated pain

Oral mucositis is a significant problem in cancer patients treated with radiation or chemotherapy, often hindering definitive cancer treatment. For patients with oral mucositis, pain is the most distressing symptom, leading to loss of orofacial function and poor quality of life. While oral mucositis has been well-described, its pathophysiology is poorly understood. Oral health professionals treating patients with mucositis have almost no effective therapies to treat or prevent oral mucositis. The purpose of this review is to (1) describe the current preclinical models of oral mucositis and their contribution to the understanding of mucositis pathophysiology, (2) explore preclinical studies on therapies targeting mucositis and discuss the clinical trials that have resulted from these preclinical studies, and (3) describe the proposed pathophysiology of oral mucositis pain and preclinical modeling of oral mucositis pain.

Palifermin for the protection and regeneration of epithelial tissues following injury: new findings in basic research and pre-clinical models

Keratinocyte growth factor (KGF) is a paracrine-acting epithelial mitogen produced by cells of mesenchymal origin, that plays an important role in protecting and repairing epithelial tissues. Pre-clinical data initially demonstrated that a recombinant truncated KGF (palifermin) could reduce gastrointestinal injury and mortality resulting from a variety of toxic exposures. Furthermore, the use of palifermin in patients with hematological malignancies reduced the incidence and duration of severe oral mucositis experienced after intensive chemoradiotherapy. Based upon these findings, as well as the observation that KGF receptors are expressed in many, if not all, epithelial tissues, pre-clinical studies have been conducted to determine the efficacy of palifermin in protecting different epithelial tissues from toxic injury in an attempt to model various clinical situations in which it might prove to be of benefit in limiting tissue damage. In this article, we review these studies to provide the pre-clinical background for clinical trials that are described in the accompanying article and the rationale for additional clinical applications of palifermin.

Keratinocyte growth factor induces gene expression signature associated with suppression of malignant phenotype of cutaneous squamous carcinoma cells

Keratinocyte growth factor (KGF, fibroblast growth factor-7) is a fibroblast-derived mitogen, which stimulates proliferation of epithelial cells. The expression of KGF by dermal fibroblasts is induced following injury and it promotes wound repair. However, the role of KGF in cutaneous carcinogenesis and cancer progression is not known. We have examined the role of KGF in progression of squamous cell carcinoma (SCC) of the skin. The expression of KGF receptor (KGFR) mRNA was lower in cutaneous SCCs (n = 6) than in normal skin samples (n = 6). Expression of KGFR mRNA was detected in 6 out of 8 cutaneous SCC cell lines and the levels were downregulated by 24-h treatment with KGF. KGF did not stimulate SCC cell proliferation, but it reduced invasion of SCC cells through collagen. Gene expression profiling of three cutaneous SCC cell lines treated with KGF for 24 h revealed a specific gene expression signature characterized by upregulation of a set of genes specifically downregulated in SCC cells compared to normal epidermal keratinocytes, including genes with tumor suppressing properties (SPRY4, DUSP4, DUSP6, LRIG1, PHLDA1). KGF also induced downregulation of a set of genes specifically upregulated in SCC cells compared to normal keratinocytes, including genes associated with tumor progression (MMP13, MATN2, CXCL10, and IGFBP3). Downregulation of MMP-13 and KGFR expression in SCC cells and HaCaT cells was mediated via ERK1/2. Activation of ERK1/2 in HaCaT cells and tumorigenic Ha-ras-transformed HaCaT cells resulted in downregulation of MMP-13 and KGFR expression. These results provide evidence, that KGF does not promote progression of cutaneous SCC, but rather suppresses the malignant phenotype of cutaneous SCC cells by regulating the expression of several genes differentially expressed in SCC cells, as compared to normal keratinocytes.

Recent advances in anti-angiogenic therapy of cancer

Since angiogenesis is critical for tumor growth and metastasis, anti-angiogenic treatment is a highly promising therapeutic approach. Thus, for over last couple of decades, there has been a robust activity aimed towards the discovery of angiogenesis inhibitors. More than forty anti-angiogenic drugs are being tested in clinical trials all over the world. This review discusses agents that have approved by the FDA and are currently in use for treating patients either as single-agents or in combination with other chemotherapeutic agents.

Three-dimensional spheroid culture of human gingiva-derived mesenchymal stem cells enhances mitigation of chemotherapy-induced oral mucositis

Mesenchymal stem cells (MSCs) are capable of regenerative and immunomodulatory functions in cell-based therapies in a variety of human diseases and injuries; however, their therapeutic efficacy and potential side effects remain major obstacles in clinical applications. We report here a 3D spheroid culture approach to optimize stem cell properties and therapeutic effects of human gingiva-derived mesenchymal stem cells (GMSCs) in mitigation of experimental oral mucositis. Under growth condition of ultra-low attachment, GMSCs spontaneously aggregated into 3D spheroids and exhibited distinct early stem cell phenotype characterized by elevated expression Stro-1 and CXC chemokine receptor 4 (CXCR-4) as well as OCT-4 and Nanog, 2 important transcriptional factors relevant to stem cell properties, and decreased expression of MSC-associated markers, including CD29, CD90, and CD105. Functionally, spheroid GMSCs are capable of enhanced multipotency and augmented secretion of several chemokines and cytokines relevant to cell migration, survival, and angiogenesis. More importantly, spheroid GMSCs expressed increased levels of reactive oxygen species, hypoxia-inducible factor (HIF)-1 and -2α, and manganese superoxide dismutase, which correlated with improved resistance to oxidative stress-induced apoptosis. Using an in vivo murine model of chemotherapy-induced oral mucositis, we demonstrated that spheroid-derived GMSCs possessed better therapeutic efficacy than their adherent cells in reversing body weight loss and promoting the regeneration of disrupted epithelial lining of the mucositic tongues. These findings suggest that 3D spheroid culture allows early stemness preservation and potentially precondition GMSCs for enhanced mitigation of oral mucositis.

Palifermin reduces severe mucositis in definitive chemoradiotherapy of locally advanced head and neck cancer: a randomized, placebo-controlled study

PURPOSE

Oral mucositis (OM) is a debilitating toxicity of chemoradiotherapy for head and neck cancer (HNC). This randomized, placebo-controlled, double-blind study evaluated the efficacy and safety of palifermin to reduce OM associated with definitive chemoradiotherapy for locally advanced HNC.

PATIENTS AND METHODS

Patients receiving conventionally fractionated radiotherapy (2.0 Gy/d, 5 days/wk to 70 Gy) with cisplatin (100 mg/m(2) on days 1, 22, and 43) received palifermin (180 μg/kg) or placebo before starting chemoradiotherapy and then once weekly for 7 weeks. The primary end point was the incidence of severe, observable, and functional OM (WHO grade 3 to 4).

RESULTS

The palifermin (n = 94) and placebo (n = 94) arms were well balanced. The incidence of severe OM was significantly lower for palifermin than for placebo (54% v 69%; P = .041). In the palifermin arm, median time to severe OM was delayed (47 v 35 days), median duration of severe OM was shortened (5 v 26 days), and the incidence of xerostomia grade ≥ 2 was lower (67% v 80%), favoring palifermin; however, the differences were not significant after multiplicity adjustment. Opioid analgesic use, average mouth and throat soreness scores, and chemoradiotherapy compliance were not significantly different between treatment arms. Adverse events were similar between arms (98%, palifermin; 93%, placebo). The most common study drug-related adverse events were rash, flushing, and dysgeusia. After median follow-up of 25.8 months, overall survival and progression-free survival were similar between treatment arms.

CONCLUSION

Although palifermin reduced severe functional OM, its role in the management of locally advanced HNC during chemoradiotherapy remains to be elucidated.

Evaluation of current and upcoming therapies in oral mucositis prevention

Cancer chemotherapy has evolved from a few therapeutic agents in three drug classes to more than 50 drugs in over ten drug classes. With generally cytotoxic mechanisms of action, there is continued research interest in preventing and managing adverse events of chemotherapy. Although treatment-induced symptom management has made significant progress, most therapies lead to intolerable reactions that result in a dose reduction or discontinuation of therapy. Mucositis is a common adverse event that can occur after administration of systemic chemotherapy and/or radiation therapy leading to inflammatory lesions anywhere from the oral cavity to the GI tract. Although pathophysiologically similar, gastrointestinal mucositis and oral mucositis (OM) differ in terms of symptom presentation and offending therapies. The focus of the article will be on OM; gastrointestinal mucositis will be mentioned when therapy efficacy is relevant to OM. OM prophylaxis has been a subject of interest for at least the past 30 years, yet progress has been limited due to a lack of understanding of the condition. With the recent introduction of palifermin (Kepivance™), novel therapies continue to be developed that may significantly reduce the incidence, duration and/or severity of OM. In addition, outcomes including an improvement in patient quality of life, increasing treatment dose intensity or reducing healthcare costs may result from successful management of OM prophylaxis. This article will review currently available OM prophylactic therapies. Agents in preclinical or clinical development and natural supplements will also be discussed.

Novel therapeutic strategies for acute lung injury induced by lung damaging agents: the potential role of growth factors as treatment options

The increasing threat from terrorism has brought attention to the possible use of toxic industrial compounds (TICs) and other lung-damaging agents as weapons against civilian populations. The way in which these agents could be used favours the development of generic countermeasures. Improved medical countermeasures would increase survivability and improve the quality of recovery of lung damaged casualties. It is evident that there is a dearth of therapeutic regimes available to treat those forms of lung damage that currently require intensive care management. It is quite possible that mass casualties from a terrorist incident or major industrial accident involving the release of large quantities of inhaled TICs would place a severe burden on already scarce intensive care facilities. The development of effective pharmacological approaches to assist the recovery of casualties suffering from acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) may improve the prognosis of such patients (which is currently poor) and would ideally be used as a means of preventing subjects from developing the pulmonary oedema characteristic of ALI/ARDS. Many promising candidate pharmacological treatments have been evaluated for the treatment of ALI/ARDS, but their clinical value is often debatable. Thus, despite improvements in ventilation strategies, pharmacological intervention for ALI/ARDS remains problematical. A new approach is clearly required for the treatment of patients with severely compromised lungs. Whilst the pathology of ALI/ARDS associated with exposure to a variety of agents is complex, numerous experimental studies suggest that generic therapeutic intervention directed at approaches that aim to upregulate repair of the damaged alveolar blood/air barrier of the lung may be of value, particularly with respect to chemical-induced injury. To this end, keratinocyte growth factor (KGF), epithelial growth factor (EGF) and basic fibroblast growth factor (bFGF) are emerging as the most important candidates. Hepatocyte growth factor (HGF) does not have epithelial specificity for lung tissue. However, the enhanced effects of combinations of growth factors, such as the synergistic effect of HGF upon vascular endothelial growth factor (VEGF)-mediated endothelial cell activity, and the combined effect of HGF and KGF in tissue repair should be investigated, particularly as the latter pair of growth factors are frequently implicated in processes associated with the repair of lung damage. Synergistic interactions also occur between trefoil factor family (TFF) peptides and growth factors such as EGF. TFF peptides are most likely to be of value as a short term therapeutic intervention strategy in stimulating epithelial spreading activities which allow damaged mucosal surfaces to be rapidly covered by epithelial cells.

Efficacy of palifermin (keratinocyte growth factor-1) in the amelioration of oral mucositis

PURPOSE

Oral mucositis is a significant toxicity of cytotoxic chemo- and radiation-therapy used to treat cancer. Palifermin is the first pharmaceutical/biological agent approved for the intervention of oral mucositis. The major objective of this review is to evaluate the evidence supporting the use of palifermin.

METHODS

A literature search was performed using an appropriate keyword search in MEDLINE and PubMed databases.

RESULTS

Of 100 full papers and 4 abstracts identified, 12 papers and 3 abstracts were appropriate for analysis. Level 2 evidence supporting palifermin use in patients with hematologic malignancies being treated with autologous hematopoietic stem cell transplantation (HSCT) is clear. Level 2 evidence also exists for the use of palifermin in the prevention of oral mucositis in patients with solid tumors (colorectal cancer, head and neck cancer), but is incomplete. Level >/= 3 data support the use of palifermin in allogeneic HSCT recipients and cycled chemotherapy. A single health economic study concluded that palifermin is essentially cost neutral in the autologous HSCT population.

CONCLUSION

Data supporting the use of palifermin in autologous HSCT recipients with hematologic malignancies is clear. Some data exist demonstrating its efficacy in other oncologic indications. Additional studies are needed to broaden the potential applications of palifermin and to ascertain its economic, but not symptomatic, effectiveness.

Palifermin for management of treatment-induced oral mucositis in cancer patients

Oral mucositis (OM) remains a major side effect of various cancer therapies, which exacts a significant price in terms of morbidity and cost of care. Efforts aimed at prevention and/or therapy of OM have been largely unsuccessful. Few agents have shown efficacy, and even those were applicable to limited types of patients. The advent of small-molecule targeted agents opened new possibilities for intervention in the mucopathogenic processes induced by cancer therapies. One of these agents, recombinant human keratinocyte growth factor (KGF), has been studied extensively and has shown promising results in reducing chemotherapy induced OM. This drug's effects on stem cell engraftment, graft-versus-host disease and other treatment-induced morbidities remain undefined. In this article we evaluate the pre-clinical and clinical evidence and discuss the clinical applications of KGF as an adjunct therapeutic agent in oncology.

Prevention of radiation-induced oral mucositis after adenoviral vector-mediated transfer of the keratinocyte growth factor cDNA to mouse submandibular glands

PURPOSE

The study aims to evaluate if human keratinocyte growth factor (hKGF), secreted after transduction of murine salivary glands with adenoviral vectors, can prevent oral mucositis resulting from radiation.

EXPERIMENTAL DESIGN

Two serotype 5 adenoviral vectors encoding hKGF were constructed: AdEF1alpha-hKGF and AdLTR(2)EF1alpha-hKGF. Female C3H mice, 8 weeks old, were irradiated by single (22.5 Gy) or fractionated (5 x 8 Gy for 5 days) doses to induce oral mucositis (ulcers on tongue). One day before irradiation, the above viral vectors or an empty vector, Adcontrol, was given (10(10) particles per gland) to both submandibular glands by retrograde ductal instillation. Each experiment included five groups: no irradiation and irradiation (+/-Adcontrol, AdEF1alpha-hKGF, or AdLTR(2)EF1alpha-hKGF). Blood, saliva, submandibular glands, and tongue were collected on day 7 for single-dose studies or day 10 for fractionated dosing. hKGF levels were measured by ELISA.

RESULTS

In three separate single-dose irradiation experiments, lingual ulcers were dramatically reduced after either KGF-expressing vector. Similarly, in two separate fractionated irradiation experiments, the hKGF-expressing vectors completely prevented ulcer formation. QPCR data indicated that approximately 10(7) to 10(8) particles of each vector remained in the targeted submandibular glands at the terminal time. Transgenic hKGF protein was found at high levels in saliva, serum, and submandibular gland extracts.

CONCLUSIONS

hKGF gene transfer to salivary glands prevented radiation-induced oral mucositis in mice. This proof of concept study suggests that transgenic hKGF secreted from transduced salivary glands may be useful clinically to prevent oral mucositis caused by radiation.