Systemic chemotherapy in the treatment of malignant melanoma

Lyophilizable Stem Cell-Hybrid Liposome with Long-Term Stability and High Targeting Capacity

The hybridization of liposome with stem cell membranes is an emerging technology to prepare the nanovehicle with the capacity of disease-responsive targeting. However, the long-term storage of this hybrid liposome has received limited attention in the literature, which is essential for its potential applicability in the clinic. Therefore, the preservation of long-term activity of stem cell-hybrid liposome using freeze-drying is investigated in the present study. Mesenchymal stem cell-hybrid liposome is synthesized and its feasibility for freeze-drying under different conditions is examined. Results reveal that pre-freezing the hybrid liposome at -20 °C in Tris buffer solution (pH 7.4) containing 10% trehalose can well preserve the liposomal structure for at least three months. Notably, major membrane proteins on the hybrid liposome are protected in this formulation and CXCR4-associated targeting capacity is maintained both in vitro and in vivo. Consequently, the hybrid liposome stored for three months demonstrates a comparable tumor inhibition as the fresh-prepared one. The present study provides the first insights into the long-term storage of stem cell hybrid liposome using lyophilization, which may make an important step forward in enhancing the long-term stability of these promising biomimetic nanovehicle and ease the logistics and the freeze-storage in the potential clinical applications.

Emerging platinum(IV) prodrug nanotherapeutics: A new epoch for platinum-based cancer therapy

Owing to the unique DNA damaging cytotoxicity, platinum (Pt)-based chemotherapy has long been the first-line choice for clinical oncology. Unfortunately, Pt drugs are restricted by the severe dose-dependent toxicity and drug resistance. Correspondingly, Pt(IV) prodrugs are developed with the aim to improve the antitumor performance of Pt drugs. However, as "free" molecules, Pt(IV) prodrugs are still subject to unsatisfactory in vivo destiny and antitumor efficacy. Recently, Pt(IV) prodrug nanotherapeutics, inheriting both the merits of Pt(IV) prodrugs and nanotherapeutics, have emerged and demonstrated the promise to address the underexploited dilemma of Pt-based cancer therapy. Herein, we summarize the latest fronts of emerging Pt(IV) prodrug nanotherapeutics. First, the basic outlines of Pt(IV) prodrug nanotherapeutics are overviewed. Afterwards, how versatile Pt(IV) prodrug nanotherapeutics overcome the multiple biological barriers of antitumor drug delivery is introduced in detail. Moreover, advanced combination therapies based on multimodal Pt(IV) prodrug nanotherapeutics are discussed with special emphasis on the synergistic mechanisms. Finally, prospects and challenges of Pt(IV) prodrug nanotherapeutics for future clinical translation are spotlighted.

Exploiting the potential of extracellular vesicles as delivery vehicles for the treatment of melanoma

Melanoma, the most aggressive skin cancer that originated from genetic mutations in the melanocytes, is still a troublesome medical problem under the current therapeutic approaches, which include surgical resection, chemotherapy, photodynamic therapy, immunotherapy, biochemotherapy and targeted therapy. Nanotechnology has significantly contributed to the development of cancer treatment in the past few years, among which extracellular vesicles (EVs) are nanosized lipid bilayer vesicles secreted from almost all cells that play essential roles in many physiological and pathological processes. In terms of melanoma therapy, the unique physicochemical properties of EVs make them promising nanocarriers for drug transportation compared to other synthetic nanocarriers. Moreover, EVs can be further engineered to maximize their drug delivery potential. Herein, in this minireview, we gave a brief overview of EV-based drug delivery strategies for melanoma therapy, in which different therapeutics delivered via EVs were summarized. We also highlighted the current progress of the EV-based delivery platform for melanoma therapy in clinical trials. The obstacles to applying exosomes in clinical practice toward further translation of EVs melanoma therapy were also discussed at the end. In summary, EVs offer promising prospects for melanoma therapy, whilst the ways for unlocking EVs’ full potential in melanoma therapies should be further investigated by solving relevant issues which hamper EVs-based melanoma therapy translation in the future.

Demographics, Pattern of Care, and Outcome Analysis of Malignant Melanomas - Experience From a Tertiary Cancer Centre in India

Background

Treatment of malignant melanoma has undergone a paradigm shift with the advent of immune checkpoint inhibitors (ICI) and targeted therapies. However, access to ICI is limited in low-middle income countries (LMICs).

Patients and Methods

Histologically confirmed malignant melanoma cases registered from 2013 to 2019 were analysed for pattern of care, safety, and efficacy of systemic therapies (ST).

Results

There were 659 patients with a median age of 53 (range 44–63) years; 58.9% were males; 55.2% were mucosal melanomas. Most common primary sites were extremities (36.6%) and anorectum (31.4%). Nearly 10.8% of the metastatic cohort were BRAF mutated. Among 368 non-metastatic patients (172 prior treated, 185 de novo, and 11 unresectable), with a median follow-up of 26 months (0–83 months), median EFS and OS were 29.5 (95% CI: 22–40) and 33.3 (95% CI: 29.5–41.2) months, respectively. In the metastatic cohort, with a median follow up of 24 (0–85) months, the median EFS for BSC was 3.1 (95% CI 1.9–4.8) months versus 3.98 (95% CI 3.2–4.7) months with any ST (HR: 0.69, 95% CI: 0.52–0.92; P = 0.011). The median OS was 3.9 (95% CI 3.3–6.4) months for BSC alone versus 12.0 (95% CI 10.5–15.1) months in any ST (HR: 0.38, 95% CI: 0.28–0.50; P < 0.001). The disease control rate was 51.55%. Commonest grade 3–4 toxicity was anemia with chemotherapy (9.5%) and ICI (8.8%). In multivariate analysis, any ST received had a better prognostic impact in the metastatic cohort.

Conclusions

Large real-world data reflects the treatment patterns adopted in LMIC for melanomas and poor access to expensive, standard of care therapies. Other systemic therapies provide meaningful clinical benefit and are worth exploring especially when the standard therapies are challenging to administer.

Intussusception induced by gastrointestinal metastasis of malignant melanoma: A case report

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Diagnosis of intestinal metastasis of malignant melanoma is difficult because it usually made after appearing symptoms of bowel obstruction.

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Emergency surgery for malignant melanoma of small intestine are often performed without enough examination preoperatively.

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Malignant melanoma tends to metastases to the small intestine simultaneously and multiply.

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When treating small intestinal metastasis of malignant melanoma, location and number of the metastasis should be understood.

Introduction

Malignant melanoma sometimes metastasizes to small intestine, and could cause various clinical symptoms, including intussusception. Among the acute abdomen cohort in Japan, it is quite rare to encounter this entity.

Presentation of case

A 68-year-old male patient was admitted to our hospital with chief complaints of abdominal pain and vomiting.　He underwent tumor resection for malignant melanoma of the primary lesion at left foot base, local recurrence and brain metastasis during the last five years. At admission, abdominal X-ray demonstrated small bowel obstruction. An ileus tube was inserted, and contrast media enema study showed crab-like shadow defect was observed in the advanced part. Enhanced computed tomography showed intussusception in the proximal jejunum caused by a tumor of 5 cm in diameter in the advanced part. No other intestinal lesion was found. Diagnosis of intussusception caused by solitary metastasis of malignant melanoma was made. Laparoscopic partial resection of the small intestine was performed. Postoperative course was uneventful, and patient was followed in outpatient clinic without further treatment with any recurrence of disease for one years.

Discussion

Malignant melanoma tends to metastases to the small intestine simultaneously and multiply. It bothers surgeons to decide range of small intestinal resection at emergency surgery. In the present study, preoperative examination allowed the adequate range of intestinal resection including location and number of metastases before operation.

Conclusion

When an acute abdomen caused by intestinal metastasis of malignant melanoma was consulted, surgeon should make effort to identify location and number of metastatic lesion, preoperatively.

Hospitalization and emergency department utilization in patients with advanced melanoma receiving pembrolizumab versus ipilimumab plus nivolumab in US academic centers

Background: Both pembrolizumab (PEMBRO) and ipilimumab + nivolumab (IPI + NIVO) are FDA-approved immunotherapy regimens for advanced melanoma (AM). Each regimen has different toxicity profiles potentially impacting healthcare resource utilization (HCRU). This study compared real-world hospitalization and emergency department (ED) utilization within 12 months of therapy initiation of each regimen.Methods: A retrospective cohort study was conducted in AM patients ≥18 years old initiating PEMBRO or IPI + NIVO between January 1, 2016-December 30, 2017. Patients were identified from 12 US-based academic and satellite centers. All-cause hospitalization ED visits were identified. These events were used to calculate rates per 1,000 patient months. Utilization between groups was compared using multivariate logistic regression.Results: In total, 400 patients were included (200 PEMBRO, 200 IPI + NIVO). PEMBRO vs IPI + NIVO patients had poorer Eastern Cooperative Group (ECOG) performance status, 29% 2-4, vs 12% (p < .001); more diabetes, 21% vs 13% (p = .045); were more often PD-L1 expression positive, 77% vs 63% (p = .011); and less likely BRAF mutant, 35% vs 50% (p = .003). The proportion with more than one hospitalization over 12 months was 17% PEMBRO vs 24% IPI + NIVO. Less than 2% had more than one admission and none had more than two. Unadjusted mean (SD) hospitalizations per 1,000 patient-months were 16 (37) and 20 (38), PEMBRO and IPI + NIVO, respectively. Adjusted odds ratio for hospitalization was 0.6 (95% CI = 0.3-0.9; p = .027) for PEMBRO vs IPI + NIVO. ED visits occurred in 18% vs 21%, PEMBRO and IPI + NIVO, respectively, 0.7 (p = .186).Conclusions: PEMBRO patients had a significantly lower probability of hospitalization through 12 months vs IPI + NIVO. The probability of ED visits did not differ.

Carbon-ion radiotherapy combined with chemotherapy for head and neck mucosal melanoma: Prospective observational study

This study aimed to evaluate the efficacy of carbon-ion radiotherapy in combination with chemotherapy using dacarbazine, nimustine, and vincristine (DAV therapy) in mucosal melanoma. Twenty-one patients with clinically localized mucosal melanoma of the head and neck were enrolled. The primary endpoint was 3-year overall survival (OS). Secondary endpoints included local control, progression-free survival (PFS), and adverse event occurrence. Carbon-ion radiotherapy with a dose of 57.6-64.0 Gy (relative biological effectiveness) in 16 fractions was delivered concurrently with DAV therapy, and 2 cycles of adjuvant DAV therapy were administered every 6 weeks. The median follow-up periods were 15.5 months for all patients, and 31.2 months for 12 surviving patients. All patients had locally advanced T4a or T4b disease in the rhino-sinus area. In 16 patients (76.2%), 3 cycles of planned DAV therapy were completed. The 3-year OS and PFS rates were 49.2% and 37.0% respectively. The 3-year local control rate was 92.3%. Eleven patients (52%) developed distant metastasis, which was the most frequent pattern of the first failure. Commonly presenting acute grade 2-3 toxicities associated with radiotherapy and chemotherapy were mucositis (11 patients [53%]) and leukopenia (9 patients [43%]), which improved with conservative therapy. None of the patients developed grade 3 or greater late toxicities. Carbon-ion radiotherapy in combination with DAV therapy led to excellent local control for advanced mucosal melanoma within acceptable toxicities. The efficacy of additional DAV therapy in improving survival was weaker than expected as distant metastases still occurred frequently. Trial registration no. UMIN000007939.

Chloroethylating nitrosoureas in cancer therapy: DNA damage, repair and cell death signaling

Chloroethylating nitrosoureas (CNU), such as lomustine, nimustine, semustine, carmustine and fotemustine are used for the treatment of malignant gliomas, brain metastases of different origin, melanomas and Hodgkin disease. They alkylate the DNA bases and give rise to the formation of monoadducts and subsequently interstrand crosslinks (ICL). ICL are critical cytotoxic DNA lesions that link the DNA strands covalently and block DNA replication and transcription. As a result, S phase progression is inhibited and cells are triggered to undergo apoptosis and necrosis, which both contribute to the effectiveness of CNU-based cancer therapy. However, tumor cells resist chemotherapy through the repair of CNU-induced DNA damage. The suicide enzyme O⁶-methylguanine-DNA methyltransferase (MGMT) removes the precursor DNA lesion O⁶-chloroethylguanine prior to its conversion into ICL. In cells lacking MGMT, the formed ICL evoke complex enzymatic networks to accomplish their removal. Here we discuss the mechanism of ICL repair as a survival strategy of healthy and cancer cells and DNA damage signaling as a mechanism contributing to CNU-induced cell death. We also discuss therapeutic implications and strategies based on sequential and simultaneous treatment with CNU and the methylating drug temozolomide.

The oncolytic peptide LTX-315 induces cell death and DAMP release by mitochondria distortion in human melanoma cells

Host defense peptides (HDPs) are naturally occurring molecules found in most species, in which they play a significant role in the first line defense against intruding pathogens, and several HDPs have been shown to possess anticancer activity. Structure-activity relationship studies on the HDP bovine lactoferricin revealed a de novo design of a nonamer peptide LTX-315, with oncolytic properties. In the present study, we investigated the oncolytic activity of LTX-315 in human melanoma cells (A375). LTX-315 induced a rapid plasma membrane disruption and cell death within 2 hours. At a low concentration, fluorescence-labeled LTX-315 was internalized and accumulated in cytoplasmic vacuoles in close proximity to the mitochondria. The mitochondrial membrane potential was shown to depolarize as a consequence of LTX-315 treatment and at ultrastructural level, the mitochondria morphology was significantly altered. Release of danger signals (DAMPs) such as ATP, Cytochrome C and HMGB1 into the cell supernatant of cultured cells was evident minutes after peptide treatment. The oncolytic effect of LTX-315 involving perturbation of both the cell membrane and the mitochondria with subsequent release of DAMPs may highlight the ability of LTX-315 to induce complete regression and long-term protective immune responses as previously reported in experimental animal models.

Endoplasmic reticulum stress-mediated pathways to both apoptosis and autophagy: Significance for melanoma treatment

Melanoma is the most aggressive form of skin cancer. Disrupted intracellular signaling pathways are responsible for melanoma's extraordinary resistance to current chemotherapeutic modalities. The pathophysiologic basis for resistance to both chemo- and radiation therapy is rooted in altered genetic and epigenetic mechanisms that, in turn, result in the impairing of cell death machinery and/or excessive activation of cell growth and survival-dependent pathways. Although most current melanoma therapies target mitochondrial dysregulation, there is increasing evidence that endoplasmic reticulum (ER) stress-associated pathways play a role in the potentiation, initiation and maintenance of cell death machinery and autophagy. This review focuses on the reliability of ER-associated pathways as therapeutic targets for melanoma treatment.

Characterization of Dynamic Behaviour of MCF7 and MCF10A Cells in Ultrasonic Field Using Modal and Harmonic Analyses

Treatment options specifically targeting tumour cells are urgently needed in order to reduce the side effects accompanied by chemo- or radiotherapy. Differences in subcellular structure between tumour and normal cells determine their specific elasticity. These structural differences can be utilised by low-frequency ultrasound in order to specifically induce cytotoxicity of tumour cells. For further evaluation, we combined in silico FEM (finite element method) analyses and in vitro assays to bolster the significance of low-frequency ultrasound for tumour treatment. FEM simulations were able to calculate the first resonance frequency of MCF7 breast tumour cells at 21 kHz in contrast to 34 kHz for the MCF10A normal breast cells, which was due to the higher elasticity and larger size of MCF7 cells. For experimental validation of the in silico-determined resonance frequencies, equipment for ultrasonic irradiation with distinct frequencies was constructed. Differences for both cell lines in their response to low-frequent ultrasonic treatment were corroborated in 2D and in 3D cell culture assays. Treatment with ~ 24.5 kHz induced the death of MCF7 cells and MDA-MB-231 metastases cells possessing a similar elasticity; frequencies of > 29 kHz resulted in cytotoxicity of MCF10A. Fractionated treatments by ultrasonic irradiation of suspension myeloid HL60 cells resulted in a significant decrease of viable cells, mostly significant after threefold irradiation in intervals of 3 h. Most importantly in regard to a clinical application, combined ultrasonic treatment and chemotherapy with paclitaxel showed a significantly increased killing of MCF7 cells compared to both monotherapies. In summary, we were able to determine for the first time for different tumour cell lines a specific frequency of low-intensity ultrasound for induction of cell ablation. The cytotoxic effect of ultrasonic irradiation could be increased by either fractionated treatment or in combination with chemotherapy. Thus, our results will open new perspectives in tumour treatment.

Systemic chemotherapy is modulated by platelet-activating factor-receptor agonists

Chemotherapy is used to treat numerous cancers including melanoma. However, its effectiveness in clinical settings is often hampered by various mechanisms. Previous studies have demonstrated that prooxidative stressor-mediated generation of oxidized lipids with platelet-activating factor-receptor (PAF-R) agonistic activity induces systemic immunosuppression that augments the growth of experimental melanoma tumors. We have recently shown that treatment of murine B16F10 melanoma cells in vitro or tumors implanted into syngeneic mice and treated intratumorally with various chemotherapeutic agents generated PAF-R agonists in a process blocked by antioxidants. Notably, these intratumoral chemotherapy-generated PAF-R agonists augmented the growth of secondary (untreated) tumors in a PAF-R dependent manner. As both localized and systemic chemotherapies are used based on tumor localization/stage and metastases, the current studies were sought to determine effects of PAF-R agonists on systemic chemotherapy against experimental melanoma. Here, we show that systemic chemotherapy with etoposide (ETOP) attenuates the growth of melanoma tumors when given subsequent to the tumor cell implantation. Importantly, this ETOP-mediated suppression of melanoma tumor growth was blocked by exogenous administration of a PAF-R agonist, CPAF. These findings indicate that PAF-R agonists not only negatively affect the ability of localized chemotherapy but also compromise the efficacy of systemic chemotherapy against murine melanoma.

Gastrointestinal bleeding as presentation of small bowel metastases of malignant melanoma: Is surgery a good choice?

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We examine two case reports about bowel metastasis of malignant melanoma.

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We consider the several methods to make a diagnosis and we would promote gastrointestinal investigations in patients with melanoma.

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We underline the importance of regular follow-up and we would stress the role of surgeon in encouraging patients and supporting the easier way to do that in order to avoid “lost to follow-up”.

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We propose surgery as a good option to control melanoma disease even if in cases of spread involvement in order to remove the source of acute symptoms and improve quality of life.

INTRODUCTION

Melanoma shows a particular predilection in involving small intestine both in a single site and in multiple localization and acute or chronic gastrointestinal bleedings are often the first sign of tumour.

PRESENTATION OF CASE

We report two cases of GI metastases of malignant melanoma, one presented with only a big mass that cause intestinal obstruction and the other with a tumour spread throughout the small intestine that produce enterorrhagia.

DISCUSSION

Diagnosis and follow-up are very difficult: CT scan, PET-CT scan and capsule endoscopy should be complementary for the assessment of patients with GI symptoms and melanoma history.

CONCLUSION

What is the role of surgery? Several studies suggest metastasectomy to achieve both R0 results and palliative resolutions of acute symptoms, such as obstruction, pain, and bleeding.

Complete regression and systemic protective immune responses obtained in B16 melanomas after treatment with LTX-315

Malignant melanoma is the most aggressive and deadliest form of skin cancer due to its highly metastatic potential, which calls for new and improved therapies. Cationic antimicrobial peptides (CAPs) are naturally occurring molecules found in most species, in which they play a significant role in the first line of defense against pathogens, and several CAPs have shown promising potential as novel anticancer agents. Structure-activity relationship studies on the CAP bovine lactoferricin allowed us to de novo design short chemically modified lytic anticancer peptides. In the present study, we investigated the in vivo antitumor effects of LTX-315 against intradermally established B16 melanomas in syngeneic mice. Intratumoral administration of LTX-315 resulted in tumor necrosis and the infiltration of immune cells into the tumor parenchyma followed by complete regression of the tumor in the majority of the animals. LTX-315 induced the release of danger-associated molecular pattern molecules such as the high mobility group box-1 protein in vitro and the subsequent upregulation of proinflammatory cytokines such as interleukin (IL) 1β, IL6 and IL18 in vivo. Animals cured by LTX-315 treatment were protected against a re-challenge with live B16 tumor cells both intradermally and intravenously. Together, our data indicate that intratumoral treatment with LTX-315 can provide local tumor control followed by protective immune responses and has potential as a new immunotherapeutic agent.

Recent advances and developments in the antitumor effect of the HVJ envelope vector on malignant melanoma: from the bench to clinical application

Inactivated Sendai virus particles (hemagglutinating virus of Japan envelope; HVJ-E) are considered to be safe and efficient non-viral vectors used for drug delivery, since they can incorporate DNA, RNA, proteins and drugs. We have recently found that HVJ-E has a novel antitumor immune effect using a colon cancer model. HVJ-E has also been shown to have both direct and immune-mediated indirect actions against malignancy. Intratumoral injection of an inactivated HVJ-E solution significantly reduced the tumor volume and prevented spontaneous lung metastasis, leading to an increased overall survival in C57/BL6 mice transplanted with B16/BL6 mouse melanoma cells, and even in immunodeficient mice transplanted with Mewo human melanoma cells. No severe adverse effects including laboratory data abnormalities or anaphylactic reactions were observed. The comprehensive mechanism(s) underlying the immunological effects of HVJ-E appear to include not only enhanced effector T cell- and/or natural killer (NK) cell-mediated immunity, but also rescue from regulatory T cell (Treg)-mediated immunosuppression, presumably through the interleukin-6 secretion from dendritic cells stimulated by HVJ-E. Since a protocol for a clinical study of HVJ-E in malignant melanoma was approved in 2009 by the ethics committee of Osaka University and of the Medical Center for Translational Research in Osaka University Hospital, a phase I/IIa study for advanced malignant melanoma patients was just started. In this review, we show several favorable results regarding the antitumor effects of HVJ-E and describe the novel mechanism underlying this tumor immune response. Since we are conducting a phase I/IIa clinical trial using HVJ-E in advanced melanoma patients on the basis of preclinical results, detailed clinical information and immune-monitoring data are also introduced. The development of new therapeutic modalities for advanced melanoma patients is urgently needed, and we hope that HVJ-E may provide one such treatment.

Patient derived cell culture and isolation of CD133⁺ putative cancer stem cells from melanoma

Despite improved treatments options for melanoma available today, patients with advanced malignant melanoma still have a poor prognosis for progression-free and overall survival. Therefore, translational research needs to provide further molecular evidence to improve targeted therapies for malignant melanomas. In the past, oncogenic mechanisms related to melanoma were extensively studied in established cell lines. On the way to more personalized treatment regimens based on individual genetic profiles, we propose to use patient-derived cell lines instead of generic cell lines. Together with high quality clinical data, especially on patient follow-up, these cells will be instrumental to better understand the molecular mechanisms behind melanoma progression. Here, we report the establishment of primary melanoma cultures from dissected fresh tumor tissue. This procedure includes mincing and dissociation of the tissue into single cells, removal of contaminations with erythrocytes and fibroblasts as well as primary culture and reliable verification of the cells' melanoma origin. Recent reports revealed that melanomas, like the majority of tumors, harbor a small subpopulation of cancer stem cells (CSCs), which seem to exclusively fuel tumor initiation and progression towards the metastatic state. One of the key markers for CSC identification and isolation in melanoma is CD133. To isolate CD133(+) CSCs from primary melanoma cultures, we have modified and optimized the Magnetic-Activated Cell Sorting (MACS) procedure from Miltenyi resulting in high sorting purity and viability of CD133(+) CSCs and CD133(-) bulk, which can be cultivated and functionally analyzed thereafter.

Cisplatin and 4-hexylresorcinol synergise to decrease metastasis and increase survival rate in an oral mucosal melanoma xenograft model: a preliminary study

The present study was undertaken to examine the effects of cisplatin plus 4-hexylresorcinol (4-HR) combination therapy on oral mucosal melanoma (OMM) using cultured primary OMM cells in a tumour xenograft model. Cultured primary OMM cells were used for the MTT assay and DNA microarray. OMM cells were implanted into the submandibular glands of nude mice. The mice were then treated with cisplatin only or cisplatin plus 4-HR. Tumour size changes, survival rate and tumour metastasis were compared between the two groups by observation, micro-positron emission tomography (PET) and histological examination. In the MTT assay, the cisplatin plus 4-HR group showed significantly higher inhibition of OMM cell growth compared to the other groups (p<0.05). DNA microarray results showed significant inhibition of matrix metalloproteinase (MMP)-2 gene expression upon 4-HR application. The necropsy and micro-PET results showed that the mice from the cisplatin-only group had more distant metastases than the mice from the cisplatin plus 4-HR combination group (p=0.002). MMP-2 expression was lower in the primary tumours in the cisplatin plus 4-HR combination group than in the cisplatin-only group (p<0.001). Overall survival was longer in mice from the cisplatin plus 4-HR combination group than in the cisplatin-only group (p=0.049). In conclusion, the combined effect of cisplatin and 4-HR resulted in fewer metastases and longer survival than cisplatin-only treatment in the OMM xenograft model.

Postoperative DAV-IFN-β therapy does not improve survival rates of stage II and stage III melanoma patients significantly

BACKGROUND

DAV-interferon (IFN)-β therapy is a combination chemotherapy of dacarbazine (DTIC), nimustine (ACNU) and vincristine (VCR) with local subcutaneous injection of IFN-β that is widely employed as postoperative adjuvant chemotherapy to treat malignant melanoma in Japan. However, the efficacy of DAV-IFN-β therapy has not been confirmed by randomized controlled trials and the benefit of DAV-IFN-β therapy has not been established yet. This study evaluated the contribution of DAV-IFN-β therapy to improve survival of postoperative patients with cutaneous melanoma. Methods Patients with stage II or III cutaneous melanoma seen at Nagoya University Hospital from January 1998 to December 2009 were eligible for this study. Disease-free survival rates and melanoma-specific survival rates were evaluated. A propensity score was calculated to control for the effects of variables related to decisions regarding the application of DAV-IFN-β therapy.

RESULTS

Eighty-two stage II and 60 stage III melanoma patients were included. In the post-matched stage II patients (17 matched pairs), the mean (± SE) disease-free survival rates were 39.9 ± 13.7% for DAV-IFN-β therapy and 73.1 ± 11.7% for non-use (hazard ratio for recurrence, 2.06; 95% CI, 0.63-6.69; P = 0.23), and the melanoma-specific survival rates were 66.2 ± 20.0% for DAV-IFN-β therapy and 86.2 ± 9.1% for non-use (hazard ratio for death, 1.09; 95% CI, 0.17-6.82; P = 0.93). In the post-matched stage III patients (nine matched pairs), the disease-free survival rates were 29.6 ± 16.4% for DAV-IFN-β therapy and 33.3 ± 15.7% for non-use (0.69; 95% CI, 0.22-2.17; P = 0.53), and the melanoma-specific survival rates were 55.6 ± 16.6% for DAV-IFN-β therapy and 44.4 ± 16.6% for non-use (0.67; 95% CI, 0.18-2.50; P = 0.55).

CONCLUSIONS

DAV-IFN-β therapy brought no significant improvement in either disease-free survival rates or melanoma-specific survival rates of patients with stage II or III cutaneous melanoma. A randomized controlled trial would be required to further evaluate the efficacy of DAV-IFN-β therapy as an adjuvant chemotherapy.

Combining stereotactic radiosurgery and systemic therapy for brain metastases: a potential role for temozolomide

Brain metastases are unfortunately very common in the natural history of many solid tumors and remain a life-threatening condition, associated with a dismal prognosis, despite many clinical trials aimed at improving outcomes. Radiation therapy options for brain metastases include whole brain radiotherapy (WBRT) and stereotactic radiosurgery (SRS). SRS avoids the potential toxicities of WBRT and is associated with excellent local control (LC) rates. However, distant intracranial failure following SRS remains a problem, suggesting that untreated intracranial micrometastatic disease is responsible for failure of treatment. The oral alkylating agent temozolomide (TMZ), which has demonstrated efficacy in primary malignant central nervous system tumors such as glioblastoma, has been used in early phase trials in the treatment of established brain metastases. Although results of these studies in established, macroscopic metastatic disease have been modest at best, there is clinical and preclinical data to suggest that TMZ is more efficacious at treating and controlling clinically undetectable intracranial micrometastatic disease. We review the available data for the primary management of brain metastases with SRS, as well as the use of TMZ in treating established brain metastases and undetectable micrometastatic disease, and suggest the role for a clinical trial with the aims of treating macroscopically visible brain metastases with SRS combined with TMZ to address microscopic, undetectable disease.

MMP2 expression is a prognostic marker for primary melanoma patients

BACKGROUND

Matrix metalloproteinase 2 (MMP2) is a collagenase, which aids tumor growth and invasion by digesting the extracellular matrix surrounding the tumor tissue. Our study examined MMP2 expression in various stages of melanoma progression and tested the prognostic significance of MMP2 expression. We also analyzed the correlation between p-Akt status and MMP2 expression in melanoma patients.

METHODS

Tissue microarray (TMA) and immunohistochemistry were employed to study the expression of MMP2. A total of 482 melanoma (330 primary and 152 metastatic) tumor biopsies and 149 nevi biopsies (49 normal and 100 dysplastic nevi) were used for the analysis. MMP2 expression was correlated with melanoma progression. Kaplan-Meier survival curve and multivariate Cox regression analysis were applied to verify the prognostic significance of MMP2 expression. The correlation between MMP2 and p-Akt expression was analyzed in 92 cases which were common in the present and the previous study on p-Akt expression.

RESULTS

Strong MMP2 expression is significantly increased in primary (25 %) and metastatic melanoma (43 %) compared to normal (5 %) and dysplastic nevi (10 %). Patients with strong MMP2 had significantly poorer survival compared to those with negative-to-moderate MMP2 expression. MMP2 expression could predict the patient survival independent of tumor thickness and ulceration. Furthermore, in our cohort study MMP2 expression was associated with p-Akt status and patient survival.

CONCLUSIONS

Strong MMP2 staining is associated with worse survival of melanoma patients and is an independent molecular prognostic factor for primary melanoma.

Selective induction of cell death in melanoma cell lines through targeting of Mcl-1 and A1

Melanoma is an often fatal form of skin cancer which is remarkably resistant against radio- and chemotherapy. Even new strategies that target RAS/RAF signaling and display unprecedented efficacy are characterized by resistance mechanisms. The targeting of survival pathways would be an attractive alternative strategy, if tumor-specific cell death can be achieved. Bcl-2 proteins play a central role in regulating survival of tumor cells. In this study, we systematically investigated the relevance of antiapoptotic Bcl-2 proteins, i.e., Bcl-2, Bcl-xL, Bcl-w, Mcl-1, and A1, in melanoma cell lines and non-malignant cells using RNAi. We found that melanoma cells required the presence of specific antiapoptotic Bcl-2 proteins: Inhibition of Mcl-1 and A1 strongly induced cell death in some melanoma cell lines, whereas non-malignant cells, i.e., primary human fibroblasts or keratinocytes were not affected. This specific sensitivity of melanoma cells was further enhanced by the combined inhibition of Mcl-1 and A1 and resulted in 60% to 80% cell death in all melanoma cell lines tested. This treatment was successfully combined with chemotherapy, which killed a substantial proportion of cells that survived Mcl-1 and A1 inhibition. Together, these results identify antiapoptotic proteins on which specifically melanoma cells rely on and, thus, provide a basis for the development of new Bcl-2 protein-targeting therapies.

Current status of primary malignant melanoma of the esophagus: clinical features, pathology, management and prognosis

Primary malignant melanoma of the esophagus (PMME) is a rare disease with an extremely poor prognosis. Up to 2011, approximately 300 cases had been reported worldwide. The average age of onset is 60.5 years old, with a prevalence of males (2:1). A typical finding of PMME is a lobular or polyploid, well-circumscribed and pigmented tumor, partly covered with normal mucosa. PMME represents various colors depending on its melanin quantity and commonly coexists with intramural metastases, melanocytosis or melanoma in situ. The tumor is located from the middle to lower thoracic esophagus. The accuracy of diagnosis from biopsy is approximately 80%, because many cases are misdiagnosed as a poorly differentiated carcinoma because of the absence of melanin granules. A definite diagnosis was made by immunohistochemical examination with positive results of S100 protein, HMB45 and neuron-specific enolase. PMME has a highly metastatic potential, and the incidence of distant metastasis at the initial diagnosis is around 40-80%. A metastatic tumor from cutaneous malignant melanoma is another pigmented esophageal tumor to be considered when making the differential diagnosis for PMME. Junctional activity with melanotic cells in the adjacent epithelium and the presence of in situ melanoma and/or a satellite tumor without a previous history of cutaneous melanoma are definitive. Most of the reported patients were treated with radical esophagectomy, which is believed to be an effective approach for localized PMME. Five-year survival rates have been achieved in 37% recently, while adjuvant therapy has not been proven to increase overall survival but plays a palliative role.

Stimulation of pulmonary immune responses by the TLR2/6 agonist MALP-2 and effect on melanoma metastasis to the lung

Given that metastasized melanoma is a fatal disease in most cases, it is tempting to develop strategies to a priori prevent metastasis. We have stimulated the pulmonary innate immune system by macrophage-activating lipopeptide-2 (MALP-2), a specific agonist at Toll-like receptor (TLR) 2/6, and investigated its impact on experimental melanoma metastasis. In C57BL/6 mice, intratracheal application of MALP-2 induced a profound influx of neutrophils and macrophages into the lung, which peaked after 24 h (sixfold increase) and returned to baseline within 72 h. Further analysis revealed that MALP-2 also markedly induced VCAM-1 expression on pulmonary blood vessels. In vitro experiments demonstrated that this adhesion molecule mediates binding of B16F10 melanoma cells. Furthermore, in vivo or in vitro treatment with MALP-2 did not significantly affect the ability of immune cells to lyse melanoma cells. As a consequence, notwithstanding the profound pulmonary immune response induction and in contrast to conclusions drawn from some previous publications, the net extent of experimental metastasis did not change significantly, regardless of the application regimen of MALP-2 prior to, concomitant with or after tumor cell inoculation. Melanoma cells stably transfected with green fluorescent protein allowed tracking of early events after tumor cell dissemination and showed that MALP-2-mediated TLR2/6 activation did not interfere with pulmonary melanoma cell arrest. Likewise, boosting the immune induction after establishment of metastases did not change the clinical outcome. These unexpected results vividly counsel caution regarding predictions of immunomodulating therapies, as multiple intertwined effects may influence the net outcome.

Biomarkers as key contributors in treating malignant melanoma metastases

Melanoma is a human neurocristopathy associated with developmental defects in the neural crest-derived epidermal melanocytes. At the present time, at least three hypotheses were identified that may explain melanoma aetiology, as follows: (1) a model of linear progression from differentiated melanocytes to metastatic cancer cells (2) a model involving the appearance of melanoma stem-like cells, and (3) an epigenetic progenitor model of cancer. Treating metastatic melanoma is one of the most serious challenges in the 21st century. This is justified because of a subpopulation of cells presenting a remarkable molecular heterogeneity, which is able to explain the drug resistance and the growing mortality rates worldwide. Fortunately, there are now evidences sustaining the importance of genetic, epigenetic, and metabolomic alterations as biomarkers for classification, staging, and better management of melanoma patients. To illustrate some fascinating insights in this field, the genes BRAF^V600E and CTLA4 have been recognized as bona fide targets to benefit melanoma patients. Our research attempts to carefully evaluate data from the literature in order to highlight the link between a molecular disease model and the key contribution of biomarkers in treating malignant melanoma metastases.

Gold(III) porphyrin 1a prolongs the survival of melanoma-bearing mice and inhibits angiogenesis

BACKGROUND

Gold(III) meso-tetraphenylporphyrin (gold-1a) has previously been shown to prolong the survival of hepatocellular carcinoma (HCC)-bearing rats and nasopharyngeal carcinoma (NPC) metastasis-bearing mice. It has also been proved to inhibit the tumor growth of mice bearing NPC, neuroblastoma and colon carcinoma. Mechanistically, gold-1a induces apoptosis, inhibits cell migration and invasion. In this study the efficacies of gold-1a in inhibiting melanoma and angiogenesis were investigated.

MATERIAL AND METHODS

A mouse melanoma model was used to investigate the efficacy of gold-1a in inhibiting angiogenesis, tumor growth and prolonging the survival of the tumor-bearing animals. The model was established by inoculation of 2 × 10(5) B16-F1 mouse melanoma cells into the right back flanks of the mice by subcutaneous inoculation. When the tumors grew to 0.2-0.4 cm in diameters, the mice were treated with gold-1a, solvent control or dacarbazine (DTIC) for comparison. Tumor sizes and animal survivals were monitored throughout the experiment. Tumor tissues were collected and immunohistochemically stained with CD31 antibodies for evaluation of intra-tumoral microvessel density (iMVD).

RESULTS AND CONCLUSION

Gold-1a significantly prolonged the survivals, reduced angiogenesis and tumor growth rates of melanoma-bearing mice. The compound induced necrosis and apoptosis in the mouse melanoma tissues. Gold-1a also downregulated the expression of genes playing roles in angiogenesis. Gold-1a may potentially be used to treat melanoma in patients.

Systematic review of medical treatment in melanoma: current status and future prospects

The incidence of melanoma is increasing worldwide, and the prognosis for patients with high-risk or advanced metastatic melanoma remains poor despite advances in the field. Standard treatment for patients with thick (≥2.0 mm) primary melanoma with or without regional metastases to lymph nodes is surgery followed by adjuvant therapy or clinical trial enrollment. Adjuvant therapy with interferon-α and cancer vaccines is discussed in detail. Patients who progress to stage IV metastatic melanoma have a median survival of ≤1 year. Standard treatment with chemotherapy yields low response rates, of which few are durable. Cytokine therapy with IL-2 achieves durable benefits in a greater fraction, but it is accompanied by severe toxicities that require the patient to be hospitalized for support during treatment. A systematic literature review of treatments for advanced, metastatic disease was conducted to present the success of current treatments and the promise of those still in clinical development that may yield incremental improvements in the treatment of advanced, metastatic melanoma.

Formulation of dacarbazine-loaded cubosomes. Part III. Physicochemical characterization

The purpose of this study was to investigate the physicochemical properties of dacarbazine-loaded cubosomes. The drug-loaded cubosome nanocarriers were prepared by a fragmentation method and then freeze dried. They were then characterized for size, morphology, thermal behavior, and crystallography using dynamic light scattering, transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD), respectively. The drug loading and encapsulation efficiency were determined by UV spectrophotometry. The results showed that the prepared dacarbazine-loaded cubosomes had mean diameters ranging from 86 to 106 nm. In addition to the TEM, the characteristic peaks from PXRD data suggested that the freeze-dried nanoformulations were indeed cubic in nature. DSC and PXRD analysis suggested the 0.06 or 0.28% w/w actual drug loaded inside cubosomes was in the amorphous or molecular state. These physicochemical characteristics would affect the nanoformulation shelf-life, efficacy, and safety.

Antitumor activity of delimotecan against human metastatic melanoma: pharmacokinetics and molecular determinants

Delimotecan (MEN 4901/T-0128) is a new cytotoxic prodrug constituted by a camptothecin analog (T-2513) bound to carboxymethyl dextran through a triglycine linker. A significant antitumor activity of delimotecan against human metastatic melanoma xenograft model Me15392 is reported. Dacarbazine, the drug approved for the treatment of metastatic melanoma, was ineffective in this melanoma model. Pharmacokinetic studies, together with the expression analysis of mRNA for enzymes involved in delimotecan metabolism, showed that T-2513 and other cytotoxic metabolites of delimotecan (SN 38 and T-0055) are generated in greater quantities in the tumor tissue than in toxicity target tissues, such as liver, thus accounting for the antitumoral activity. Moreover, we demonstrated that human metastatic melanoma cells are able to phagocytose delimotecan and cleave it to release the cytotoxic moieties T-2513 in the tumoral environment. Further flow cytometric analysis showed a higher recruitment of macrophages in xenografted human metastatic melanoma, when compared with other human tumors. Thus, the antitumoral activity of delimotecan exerted on metastatic melanoma is due to several factors: (i) the ability of melanoma cells to phagocytose and metabolise delimotecan; (ii) the accumulation of delimotecan in tumoral mass; (iii) the recruitment of macrophage cells to the melanoma nodule and (iv) the expression in melanoma cells of a pattern of enzymes that converts delimotecan into cytotoxic metabolites. Based on these results, delimotecan might be exploited as a new anticancer agent for the therapy of metastatic melanoma because of its high efficacy and good selectivity, and therefore clinical trials for this indication are warranted.

Formulation of dacarbazine-loaded cubosomes-part I: influence of formulation variables

The purpose of this study was to investigate the combined influence of three-level, three-factor variables on the formulation of dacarbazine (a water-soluble drug) loaded cubosomes. Box-Behnken design was used to obtain a second-order polynomial equation with interaction terms to predict response values. In this study, the selected and coded variables X(1), X(2), and X(3) representing the amount of monoolein, polymer, and drug as the independent variables, respectively. Fifteen runs of experiments were conducted, and the particle size (Y(1)) and encapsulation efficiency (Y(2)) were evaluated as dependent variables. We performed multiple regression to establish a full-model second-order polynomial equation relating independent and dependent variables. A second-order polynomial regression model was constructed for Y(1) and confirmed by performing checkpoint analysis. The optimization process and Pareto charts were obtained automatically, and they predicted the levels of independent coded variables X(1), X(2), and X(3) (-1, 0.53485, and -1, respectively) and minimized Y(1) while maximizing Y(2). These corresponded to a cubosome formulation made from 100 mg of monoolein, 107 mg of polymer, and 2 mg with average diameter of 104.7 nm and an encapsulation efficiency of 6.9%. The Box-Behnken design proved to be a useful tool to optimize the particle size of these drug-loaded cubosomes. For encapsulation efficiency (Y(2)), further studies are needed to identify appropriate regression model.

Melanoma of the small intestine

Intestinal melanomas can be primary tumours or metastases of cutaneous, ocular, or anal melanomas. Primary intestinal melanoma is extremely rare, whereas metastatic melanoma of the small bowel is common because of the tendency for cutaneous melanoma to metastasise to the gastrointestinal tract. Because distinguishing between primary and metastatic intestinal melanoma can be difficult, the main features of each are discussed, and the diagnostic images used to detect intestinal melanoma are assessed. Routine barium examinations and CT have limited sensitivity, but PET imaging can improve detection of melanoma metastases to the small bowel. Although various treatment strategies have been tried in patients with intestinal melanoma, surgical removal of intestinal metastases is the treatment of choice in patients with resectable tumours. No systemic therapy improves survival in patients with melanoma metastatic to the intestines; thus, the prognosis for these patients is poor. Patients with primary melanoma of the small intestine have a worse prognosis than do patients with metastases of cutaneous melanoma.

Characterization of highly stable liposomal and immunoliposomal formulations of vincristine and vinblastine

Purpose

Liposome and immunoliposome formulations of two vinca alkaloids, vincristine and vinblastine, were prepared using intraliposomal triethylammonium sucroseoctasulfate and examined for their ability to stabilize the drug for targeted drug delivery in vivo.

Methods

The pharmacokinetics of both the encapsulated drug (vincristine or vinblastine) and liposomal carrier were examined in Sprague Dawley rats, and the in vivo drug release rates determined. Anti-HER2 immunoliposomal vincristine was prepared from a human anti-HER2/neu scFv and studied for targeted cytotoxic activity in cell culture, and antitumor efficacy in vivo.

Results

Nanoliposome formulations of vincristine and vinblastine demonstrated similar pharmacokinetic profiles for the liposomal carrier, but increased clearance for liposome encapsulated vinblastine (t_1/2 = 9.7 h) relative to vincristine (t_1/2 = 18.5 h). Immunoliposome formulations of vincristine targeted to HER2 using an anti-HER2 scFv antibody fragment displayed a marked enhancement in cytotoxicity when compared to non-targeted liposomal vincristine control; 63- or 253-fold for BT474 and SKBR3 breast cancer cells, respectively. Target-specific activity was also demonstrated in HER2-overexpressing human tumor xenografts, where the HER2-targeted formulation was significantly more efficacious than either free vincristine or non-targeted liposomal vincristine.

Conclusions

These results demonstrate that active targeting of solid tumors with liposomal formulations of vincristine is possible when the resulting immunoliposomes are sufficiently stabilized.

Chemotherapy enhances vaccine-induced antitumor immunity in melanoma patients

Combination of chemotherapy with cancer vaccines is currently regarded as a potentially valuable therapeutic approach for the treatment of some metastatic tumors, but optimal modalities remain unknown. We designed a phase I/II pilot study for evaluating the effects of dacarbazine (DTIC) on the immune response in HLA-A2(+) disease-free melanoma patients who received anticancer vaccination 1 day following chemotherapy (800 mg/mq i.v.). The vaccine, consisting of a combination of HLA-A2 restricted melanoma antigen A (Melan-A/MART-1) and gp100 analog peptides (250 microg each, i.d.), was administered in combination or not with DTIC to 2 patient groups. The combined treatment is nontoxic. The comparative immune monitoring demonstrates that patients receiving DTIC 1 day before the vaccination have a significantly improved long-lasting memory CD8(+) T cell response. Of relevance, these CD8(+) T cells recognize and lyse HLA-A2(+)/Melan-A(+) tumor cell lines. Global transcriptional analysis of peripheral blood mononuclear cells (PBMC) revealed a DTIC-induced activation of genes involved in cytokine production, leukocyte activation, immune response and cell motility that can favorably condition tumor antigen-specific CD8(+) T cell responses. This study represents a proof in humans of a chemotherapy-induced enhancement of CD8(+) memory T cell response to cancer vaccines, which opens new opportunities to design novel effective combined therapies improving cancer vaccination effectiveness.

The role of estrogen receptor in melanoma

The estrogen receptor (ER) belongs to the group of sex hormone receptors and binds the biologically active form of estrogen, 17beta-estradiol. Expression of ER in tumor tissue is a well-established prognostic marker in breast cancer. The role of ER has been extensively studied in several other types of human cancers. This report investigates the potential role of ER as a surrogate marker for predicting melanoma progression, response to therapy, and patient survival. In addition, the authors review what is known, so far, about ER signaling pathways and their potential role in carcinogenesis and progression of cutaneous melanoma. Possibilities and limitations of using ER as a therapeutic target in the treatment of melanoma is also discussed.

Prognostic Significance of Nuclear ING3 Expression in Human Cutaneous Melanoma

PURPOSE

The novel tumor-suppressor ING3 has been shown to modulate transcription, cell cycle control, and apoptosis. Our previous study showed that ING3 promotes UV-induced apoptosis via the Fas/caspase-8-dependent pathway in melanoma cells. To investigate the putative role of ING3 in the development of melanoma, we examined the expression of ING3 in melanocytic lesions at different stages and analyzed the correlation between ING3 expression and clinicopathologic variables and patient survival.

EXPERIMENTAL DESIGN

Using tissue microarray and immunohistochemistry, we evaluated nuclear and cytoplasmic ING3 staining in 58 dysplastic nevi, 114 primary melanomas, and 50 metastatic melanomas.

RESULTS

Nuclear ING3 expression was remarkably reduced in malignant melanomas compared with dysplastic nevi (P<0.001), which was significantly correlated with the increased ING3 level in cytoplasm (P<0.05). Furthermore, the reduced nuclear ING3 expression was significantly correlated with a poorer disease-specific 5-year survival of patients with primary melanoma, especially for the high-risk melanomas (thickness >or=2.0 mm) with the survival rate reducing from 93% for patients with strong nuclear ING3 staining in their tumor biopsies to 44% for those with negative-to-moderate nuclear ING3 staining (P=0.004). Strikingly, our multivariate Cox regression analysis revealed that reduced nuclear ING3 expression is an independent prognostic factor to predict patient outcome in primary melanomas (P=0.038).

CONCLUSIONS

Our data indicate that ING3 may be an important marker for human melanoma progression and prognosis as well as a potential therapeutic target.

A Phase I Study of an Anti-GD3 Monoclonal Antibody, KW-2871, in Patients with Metastatic Melanoma

PURPOSE

KW-2871 (IgG1 kappa chimeric antibody) targets GD3, which is upregulated in melanomas. We conducted a phase I trial of KW-2871 in patients with metastatic melanoma.

METHODS

Seventeen (17) patients were enrolled and received an initial test dose (10 mg/m2) intravenously. Two 2 weeks later, patients were stratified into 4 cohorts to receive 4 doses of KW-2871 (infused over 1 hour) at 2-week intervals (20, 40, 60, and 80 mg/m2). No premedications were administered for the test or first therapeutic doses.

RESULTS

Dose-limiting toxicities were Grade 3 laryngospasm and chest tightness with the initial therapeutic infusion at doses of 80 and 60 mg/m2. The maximum tolerated dose (MTD) was established at 40 mg/m2 of KW2871. The most common side-effect was urticaria (Grades 1-3) in 16 of 16 patients during an initial therapeutic infusion without premedication. The mean terminal half-life, clearance, and area under the concentration-time curve (AUC(0-t)) at a dose of 40 mg/m2 for course 1 were 146 +/- 31 hours, 28 +/- 6 ml/hour, and 1922 +/- 491 mcg*hour/mL, respectively. Anti-human chimeric antibody was not detected. Two (2) patients in the 40 mg/m2 cohort had stable disease.

CONCLUSIONS

An MTD of 40 mg/m2 without premedication was established for KW-2871, with urticaria being the most common side-effect and dose-limiting anaphylactoid infusion reactions.

mda-7/IL-24: multifunctional cancer-specific apoptosis-inducing cytokine

"Differentiation therapy" provides a unique and potentially effective, less toxic treatment paradigm for cancer. Moreover, combining "differentiation therapy" with molecular approaches presents an unparalleled opportunity to identify and clone genes mediating cancer growth control, differentiation, senescence, and programmed cell death (apoptosis). Subtraction hybridization applied to human melanoma cells induced to terminally differentiate by treatment with fibroblast interferon (IFN-beta) plus mezerein (MEZ) permitted cloning of melanoma differentiation associated (mda) genes. Founded on its novel properties, one particular mda gene, mda-7, now classified as a member of the interleukin (IL)-10 gene family (IL-24) because of conserved structure, chromosomal location, and cytokine-like properties has become the focus of attention of multiple laboratories. When administered by transfection or adenovirus-transduction into a spectrum of tumor cell types, melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24) induces apoptosis, whereas no toxicity is apparent in normal cells. mda-7/IL-24 displays potent "bystander antitumor" activity and also has the capacity to enhance radiation lethality, to induce immune-regulatory activities, and to inhibit tumor angiogenesis. Based on these remarkable attributes and effective antitumor therapy in animal models, this cytokine has taken the important step of entering the clinic. In a Phase I clinical trial, intratumoral injections of adenovirus-administered mda-7/IL-24 (Ad.mda-7) was safe, elicited tumor-regulatory and immune-activating processes, and provided clinically significant activity. This review highlights our current understanding of the diverse activities and properties of this novel cytokine, with potential to become a prominent gene therapy for cancer.

Inactivation of O6-alkylguanine DNA alkyltransferase as a means to enhance chemotherapy

DNA adducts at the O6-position of guanine are a result of the carcinogenic, mutagenic and cytotoxic actions of methylating and chloroethylating agents. The presence of the DNA repair protein O6-alkylguanine-DNA alkyltransferase (AGT) renders cells resistant to the biological effects induced by agents that attack at this position. O6-Benzylguanine (O6-BG) is a low molecular weight substrate of AGT and therefore, results in sensitizing cells and tumors to alkylating agent-induced cytotoxicity and antitumor activity. Presently, chemotherapy regimens of O6-BG in combination with BCNU, temozolomide and Gliadel are in clinical development. Other ongoing clinical trials include expression of mutant AGT proteins that confer resistance to O6-BG in bone marrow stem cells, in an effort to reduce the potential enhanced toxicity and mutagenicity of alkylating agents in the bone marrow. O6-BG has also been found to enhance the cytotoxicity of agents that do not form adducts at the O6-position of DNA, including platinating agents. O6-BG's mechanism of action with these agents is not fully understood; however, it is independent of AGT activity or AGT inactivation. A better understanding of the effects of this agent will contribute to its clinical usefulness and the design of better analogs to further improve cancer chemotherapy.

Pegylated Arginine Deiminase Treatment of Patients With Metastatic Melanoma: Results From Phase I and II Studies

Purpose

Individuals with metastatic melanoma have a poor prognosis. Many human melanomas are auxotrophic for arginine, and arginine is not an essential amino acid in humans. We hypothesized that this auxotrophy may be therapeutically exploited. A novel amino acid–degrading enzyme (arginine deiminase) conjugated to polyethylene glycol (ADI-SS PEG 20,000 mw) was used to lower plasma arginine in individuals with metastatic melanoma.

Patients and Methods

Two cohort dose-escalation studies were performed. A phase I study in the United States enrolled 15 patients, and a phase I to II study in Italy enrolled 24 patients. The Italian patients also received two subsequent cycles of treatment, each consisting of four once-weekly injections of 160 U/m2. The goals of these studies were to determine pharmacokinetics (PK), pharmacodynamics (PD), safety, and the antitumor activity of ADI-SS PEG 20,000 mw.

Results

PK and PD studies indicated that a dose of 160 U/m2 lowered plasma arginine from a resting level of approximately 130 μmol/L to less than 2 μmol/L for at least 7 days; nitric oxide levels also were lowered. There were no grade 3 or 4 toxicities directly attributable to the drug. Six of 24 phase I to II patients responded to treatment (five partial responses and one complete response; 25% response rate) and also had prolonged survival.

Conclusion

Elimination of all detectable plasma arginine in patients with metastatic melanoma was well tolerated and may be effective in the treatment of this cancer. Further testing of ADI-SS PEG 20,000 mw in a larger population of individuals with metastatic melanoma is warranted.

Transfection of melanoma cells with antisense PAX3 oligonucleotides additively complements cisplatin-induced cytotoxicity

Advanced melanoma is difficult to treat, in part because of greater resistance to therapy compared with other cancer types. The mechanisms underlying this resistance are not well-understood. One factor that is reported to be involved in melanoma cell survival is PAX3, a transcription factor normally expressed during embryonic development, and which is critically required for development of neural crest-derivatives, including skin melanocytes. PAX3 expression is deregulated in primary melanomas and most melanoma cell lines. Here we have investigated whether targeting PAX3 expression in melanoma cell lines together with chemotherapeutic treatment increases susceptibility to therapeutic cell death. Using PAX3-specific antisense oligodeoxynucleotides (PAX3-AS) to treat melanoma cell lines in vitro, we showed dose-dependent reduction of proliferation of melanoma cells, and induction of apoptosis compared with control treatments. Induction of apoptosis was accompanied by the induction of active caspase-3 in UACC62 and M14 cells, and p53 protein in UACC62 cells. Treatment of melanoma cells with cisplatin induces DNA damage and cytotoxicity, which is thought to be via p53-dependent and -independent mechanisms. Treatment of either p53 mutant (M14) or wild-type (UACC62) melanoma cells with cisplatin, and varying doses of PAX3-AS, resulted in percentages of cells undergoing apoptosis equivalent to the sum of the individual treatments, irrespective of mutation status [e.g., UACC62, 43.8% (1 micromol/L PAX3-AS), 30.1% (20 micromol/L cisplatin), 69.6% (PAX3-AS + cisplatin); M14, 12.6% (1 micromol/L PAX3-AS), 41.5% (40 micromol/L cisplatin), 50.2% (PAX3-AS + cisplatin)]. These data suggest that treatment of melanoma cells with PAX3-AS complements cytotoxicity induced by cisplatin.

[Primary melanoma of the rectum: an infrequent neoplasia with an atypical presentation]

Primary anorectal melanoma is a rare malignancy with an extremely aggressive biological behaviour. The main clinical presentations are local symptoms such as rectal bleeding, anal mass or pain, or a change in bowel habits. The tumour is frequently mistaken for benign conditions as haemorrhoids or rectal polyps. Many treatments can be used: surgery, chemotherapy, radiotherapy, immunotherapy and even bio-therapy. Despite this, the disease has a very poor prognosis and 10% of patients survive 5 years.

Differential Regulation of Noxa in Normal Melanocytes and Melanoma Cells by Proteasome Inhibition: Therapeutic Implications

Melanoma is the most aggressive form of skin cancer and advanced stages are invariably resistant to conventional therapeutic agents. Using bortezomib as a prototypic proteasome inhibitor, we have identified a novel and critical role of the proteasome in the maintenance of the malignant phenotype of melanoma cells that could have direct translational implications. Thus, melanoma cells from early, intermediate, and late stages of the disease could not sustain proteasome inhibition and underwent an effective activation of caspase-dependent and -independent death programs. This effect was tumor cell selective, because under similar conditions, normal melanocytes remained viable. Intriguingly, and despite of interfering with a cellular machinery in charge of controlling the half-life of the vast majority of cellular proteins, bortezomib did not promote a generalized disruption of melanoma-associated survival factors (including NF-kappaB, Bcl-2, Bcl-x(L), XIAP, TRAF-2, or FLIP). Instead, we identified a dramatic induction in vitro and in vivo of the BH3-only protein Noxa in melanoma cells (but not in normal melanocytes) in response to proteasome inhibition. RNA interference validated a critical role of Noxa for the cytotoxic effect of bortezomib. Notably, the proteasome-dependent regulation of Noxa was found to extend to other tumor types, and it could not be recapitulated by standard chemotherapeutic drugs. In summary, our results revealed Noxa as a new biomarker to gauge the efficacy of bortezomib specifically in tumor cells, and provide a new strategy to overcome tumor chemoresistance.

Human Malignant Melanomas Express Receptors for Luteinizing Hormone Releasing Hormone Allowing Targeted Therapy with Cytotoxic Luteinizing Hormone Releasing Hormone Analogue

Cytotoxic analogue of luteinizing hormone releasing hormone (LHRH), AN-207, binds with high affinity to LHRH receptors and can be targeted to tumors expressing these receptors. We investigated the expression of LHRH receptors in surgical specimens of human malignant melanoma and evaluated the effects of AN-207 in models of human melanoma. Human melanoma specimens derived from primary tumors or metastases were examined for LHRH receptor expression by immunohistochemistry. Binding assays, Western immunoblotting, and reverse transcription-PCR analyses were used to investigate LHRH receptors in MRI-H255 and MRI-H187 transplantable human melanoma tumor lines. Antitumor effects of AN-207 and its components were evaluated in vivo in nude mice bearing xenografts of either melanoma tumor line. All 19 human melanoma specimens examined showed positive staining for LHRH receptors. The mRNA for LHRH receptors, receptor protein and binding sites for LHRH were detected in both transplantable melanoma tumor lines. AN-207 significantly inhibited the growth of MRI-H255 and MRI-H187 xenografts in vivo, reducing tumor volume by 59.9% to 79.2% and tumor weight by 61.0% to 76.9% (all P < 0.05). The components of AN-207 (LH-RH analogue carrier and cytotoxic radical AN-201 as single drugs or as an unconjugated mixture) had no significant effects. Blockade of LHRH receptors by an excess of LHRH agonist Decapeptyl suppressed the effects of AN-207. LHRH receptors are expressed in a very high percentage of human malignant melanoma specimens and can be used for targeted chemotherapy with cytotoxic LHRH analogue AN-207.