A study of paclitaxel, carboplatin, and bortezomib in the treatment of metastatic malignant melanoma: a phase 2 consortium study

Nano-based formulations of curcumin: elucidating the potential benefits and future prospects in skin cancer

Skin cancer refers to any malignant lesions that occur in the skin and are observed predominantly in populations of European descent. Conventional treatment modalities such as excision biopsy, chemotherapy, radiotherapy, immunotherapy, electrodesiccation, and photodynamic therapy (PDT) induce several unintended side effects which affect a patient's quality of life and physical well-being. Therefore, spice-derived nutraceuticals like curcumin, which are well tolerated, less expensive, and relatively safe, have been considered a promising agent for skin cancer treatment. Curcumin, a chemical constituent extracted from the Indian spice, turmeric, and its analogues has been used in various mammalian cancers including skin cancer. Curcumin has anti-neoplastic activity by triggering the process of apoptosis and preventing the multiplication and infiltration of the cancer cells by inhibiting some signaling pathways and thus subsequently preventing the process of carcinogenesis. Curcumin is also a photosensitizer and has been used in PDT. The major limitations associated with curcumin are poor bioavailability, instability, limited permeation into the skin, and lack of solubility in water. This will constrain the use of curcumin in clinical settings. Hence, developing a proper formulation that can ideally release curcumin to its targeted site is important. So, several nanoformulations based on curcumin have been established such as nanogels, nanoemulsions, nanofibers, nanopatterned films, nanoliposomes and nanoniosomes, nanodisks, and cyclodextrins. The present review mainly focuses on curcumin and its analogues as therapeutic agents for treating different types of skin cancers. The significance of using various nanoformulations as well non-nanoformulations loaded with curcumin as an effective treatment modality for skin cancer is also emphasized.

Synergetic effect of high dose rate radiations (10× FFF/2400 MU/min/10 MV x-rays) and paclitaxel selectively eliminates melanoma cells

BACKGROUND

Melanoma is one of the most aggressive cancers, with 1.6% of total cancer deaths in the United States. In recent years treatment options for metastatic melanoma have been improved by the FDA approval of new therapeutic agents. However, these inhibitors-based therapies are non-specific and have severe toxicities, including hyperkeratosis, photosensitivity, hepatitis, arthralgia, and fatigue.

AIMS

The aim of this study is to determine the synthetic lethal effect (paclitaxel and radiations) on melanoma cells and reduce the total radiation doses by increasing the dose rates up to 2400 MU/min.

METHODS AND RESULTS

We previously reported a radiation treatment (10 MV x-rays, 10X-FFF, dose rate 2400MU/min, low total dose 0.5 Gy) that kills melanoma cells with 80% survival of normal HEM in vitro. In this study, we extended the radiation cycle up to four and included paclitaxel treatment to study the synthetic lethal effect on melanoma and two other normal primary cells, HDF and HEK. Cells were treated with paclitaxel prior to the radiation at a dose rate of 400 and 2400 MU/min with a total radiation dose of only 0.5 Gy. Mitochondrial respiration assay, DNA damage assay, and colony formation assays were performed to study apoptosis and cell death induction. Four days of consequent radiation treatment with paclitaxel significantly reduces the survival of melanoma cells by inducing apoptosis and mitochondrial damage. After treatment, excessive DNA damage in melanoma cells leads to an increase in the expression of pro-apoptotic genes (Caspase-3) and a decrease in the expression of DNA repair gene (PARP1) and anti-apoptotic gene (Bcl-2) to activate the apoptosis pathway. The combination of paclitaxel and radiation reduces the survival of melanoma cells colonies compared to radiation alone.

CONCLUSION

Our study indicates that radiations with paclitaxel have a potential synthetic lethal effect on melanoma cells and can be developed as a melanoma therapy without toxicities or harmful effects on normal primary skin cells.

Carboplatin activates the cGAS-STING pathway by upregulating the TREX-1 (three prime repair exonuclease 1) expression in human melanoma

Human melanoma is a highly aggressive type of cancer, causing significant mortalities despite the advances in treatment. Carboplatin is a cisplatin analog necessary for the treatment of various cancers and can also be used to treat human melanoma. We assessed the effects and mechanisms leading to inhibited proliferation and induced apoptosis of human melanoma after carboplatin therapy in vitro and in vivo. TREX1, cGAS/STING, and apoptotic protein expressions were determined through RT-qPCR and western blot assays. Cell proliferation was validated through MTT assays. The study used SK-MEL-1 and SK-HEP-1 tumor cell line inoculations along with carboplatin in nude mice to validate the results. The TREX1 levels were down-regulated in human melanoma cell lines. TREX1 overexpression-induced apoptosis and decreased proliferation in the human melanoma cell lines. TREX1 overexpression also activated the cGAS/STING pathway to induce apoptosis and decrease cell growth. Carboplatin activated TREX1, induced apoptosis, and decreased proliferation in the human melanoma cancerous cell lines. Finally, carboplatin reduced the in-vivo tumor size and weight. In conclusion, the study revealed that carboplatin activated TREX1 and cGAS/STING pathways to upregulate apoptosis. The work also provides in vitro and in vivo evidence to understand the effects of TREX overexpression on tumor suppression. Targeting of TREX1/cGAS/STING pathway could be an effective therapeutic alternative to human melanoma.

Molecular Markers and Targets in Melanoma

Melanoma develops as a result of several genetic alterations, with UV radiation often acting as a mutagenic risk factor. Deep knowledge of the molecular signaling pathways of different types of melanoma allows better characterization and provides tools for the development of therapies based on the intervention of signals promoted by these cascades. The latest World Health Organization classification acknowledged the specific genetic drivers leading to melanoma and classifies melanocytic lesions into nine distinct categories according to the associate cumulative sun damage (CSD), which correlates with the molecular alterations of tumors. The largest groups are melanomas associated with low-CSD or superficial spreading melanomas, characterized by frequent presentation of the BRAFV600 mutation. High-CSD melanomas include lentigo maligna type and desmoplastic melanomas, which often have a high mutation burden and can harbor NRAS, BRAFnon-V600E, or NF1 mutations. Non-CSD-associated melanomas encompass acral and mucosal melanomas that usually do not show BRAF, NRAS, or NF1 mutations (triple wild-type), but in a subset may have KIT or SF3B1 mutations. To improve survival, these driver alterations can be treated with targeted therapy achieving significant antitumor activity. In recent years, relevant improvement in the prognosis and survival of patients with melanoma has been achieved, since the introduction of BRAF/MEK tyrosine kinase inhibitors and immune checkpoint inhibitors. In this review, we describe the current knowledge of molecular pathways and discuss current and potential therapeutic targets in melanoma, focusing on their clinical relevance of development.

Proteasome inhibitors decrease paclitaxel‑induced cell death in nasopharyngeal carcinoma with the accumulation of CDK1/cyclin B1

Southeast Asia is a region with high incidence of nasopharyngeal carcinoma (NPC). Paclitaxel is the mainstay for the treatment of advanced nasopharyngeal cancer. The present study investigated the effect of proteasome inhibitors on the therapeutic effect of paclitaxel and its related mechanism. The present data from Cell Counting Kit-8 and flow cytometry assays demonstrated that appropriate concentrations of proteasome inhibitors (30 nM PS341 or 700 nM MG132) reduced the lethal effect of paclitaxel on the nasopharyngeal cancer cells. While 400 nM paclitaxel effectively inhibited cell division and induced cell death, proteasome inhibitors (PS341 30 nM or MG132 700 nM) could reverse these effects. Additionally, the western blotting results demonstrated accumulation of cell cycle regulation protein CDK1 and cyclin B1 in proteasome inhibitor-treated cells. In addition, proteasome inhibitors combined with paclitaxel led to decreased MCL1 apoptosis regulator, BCL2 family member/Caspase-9/poly (ADP-ribose) polymerase apoptosis signaling triggered by CDK1/cyclin B1. Therefore, dysfunction of CDK1/cyclin B1 could be defining the loss of paclitaxel lethality against cancer cells, a phenomenon affirmed by the CDK1 inhibitor Ro3306. Overall, the present results demonstrated that a combination of paclitaxel with proteasome inhibitors or CDK1 inhibitors is antagonistic to effective clinical management of NPC.

Does the proteasome inhibitor bortezomib sensitize to DNA-damaging therapy in gastroenteropancreatic neuroendocrine neoplasms? - A preclinical assessment in vitro and in vivo

BACKGROUND

Well-differentiated gastroenteropancreatic neuroendocrine neoplasms are rare tumors with a slow proliferation. They are virtually resistant to many DNA-damaging therapeutic approaches, such as chemo- and external beam therapy, which might be overcome by DNA damage inhibition induced by proteasome inhibitors such as bortezomib.

METHODS AND RESULTS

In this study, we assessed several combined treatment modalities in vitro and in vivo. By cell-based functional analyses, in a 3D in ovo and an orthotopic mouse model, we demonstrated sensitizing effects of bortezomib combined with cisplatin, radiation and peptide receptor radionuclide therapy (PRRT). By gene expression profiling and western blot, we explored the underlying mechanisms, which resulted in an impaired DNA damage repair. Therapy-induced DNA damage triggered extrinsic proapoptotic signaling as well as the induction of cell cycle arrest, leading to a decreased vital tumor volume and altered tissue composition shown by magnetic resonance imaging and F-18-FDG-PET in vivo, however with no significant additional benefit related to PRRT alone.

CONCLUSIONS

We demonstrated that bortezomib has short-term sensitizing effects when combined with DNA damaging therapy by interfering with DNA repair in vitro and in ovo. Nevertheless, due to high tumor heterogeneity after PRRT in long-term observations, we were not able to prove a therapeutic advantage of bortezomib-combined PRRT in an in vivo mouse model.

Modulation of stress and immune response by Amblyomin-X results in tumor cell death in a horse melanoma model

We have investigated Amblyomin-X-treated horse melanomas to better understand its mode of action through transcriptome analysis and the in vivo model. Amblyomin-X is a Kunitz-type homologous protein that selectively leads to the death of tumor cells via ER stress and apoptosis, currently under investigation as a new drug candidate for cancer treatment. Melanomas are immunogenic tumors, and a better understanding of the immune responses is warranted. Equine melanomas are spontaneous and not so aggressive as human melanomas are, as this study shows that the in vivo treatment of encapsulated horse melanoma tumors led to a significant reduction in the tumor size or even the complete disappearance of the tumor mass through intratumoral injections of Amblyomin-X. Transcriptome analysis identified ER- and mitochondria-stress, modulation of the innate immune system, apoptosis, and possibly immunogenic cell death activation. Interactome analysis showed that Amblyomin-X potentially interacts with key elements found in transcriptomics. Taken together, Amblyomin-X modulated the tumor immune microenvironment in different ways, at least contributing to induce tumor cell death.

Rho-ROCK Signaling in Normal Physiology and as a Key Player in Shaping the Tumor Microenvironment

The Rho-ROCK signaling network has a range of specialized functions of key biological importance, including control of essential developmental processes such as morphogenesis and physiological processes including homeostasis, immunity, and wound healing. Deregulation of Rho-ROCK signaling actively contributes to multiple pathological conditions, and plays a major role in cancer development and progression. This dynamic network is critical in modulating the intricate communication between tumor cells, surrounding diverse stromal cells and the matrix, shaping the ever-changing microenvironment of aggressive tumors. In this chapter, we overview the complex regulation of the Rho-ROCK signaling axis, its role in health and disease, and analyze progress made with key approaches targeting the Rho-ROCK pathway for therapeutic benefit. Finally, we conclude by outlining likely future trends and key questions in the field of Rho-ROCK research, in particular surrounding Rho-ROCK signaling within the tumor microenvironment.

Nuclear Factor Kappa-B Is Enriched in Eyelid Specimens of Rosacea: Implications for Pathogenesis and Therapy

PURPOSE

To assess the role of nuclear factor kappa-B (NFKB) in cutaneous specimens of rosacea and unaffected tissue.

METHODS

Immunohistochemical staining was performed for the activated, phosphorylated variant of NFKB (pNFKB) in eyelid specimens of rosacea (n = 12) and normal, healthy tissue (n = 12). The numbers of positively staining cells/40× microscopic field were counted across 5 consecutive fields. Additionally, quantitative Western blotting was carried out for pNFKB and NFKB in specimens of rosacea (n = 15) and normal controls (n = 14). Statistical comparisons were performed via a dedicated software package.

RESULTS

The mean number of cells/40× microscopic field that stained positively for pNFKB was 18.4 (standard deviation = 15.3) for control patients and 39.3 (standard deviation = 16.9) for rosacea patients, and the difference between the 2 groups was statistically significant (P = .0024). On Western blotting, the mean ratios of pNFKB:NFKB for control and rosacea patients measured 0.58 (standard deviation = 0.81) and 3.11 (standard deviation = 3.53), respectively. The 2 groups were statistically significantly different (P = .0002).

CONCLUSIONS

The activated form of NFKB is enriched in rosacea, indicating a role for this pathway in the pathogenesis of this disease. Interference with NFKB signaling may represent a novel therapy for rosacea as clinical agents become available. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Regional Activation of Myosin II in Cancer Cells Drives Tumor Progression via a Secretory Cross-Talk with the Immune Microenvironment

ROCK-Myosin II drives fast rounded-amoeboid migration in cancer cells during metastatic dissemination. Analysis of human melanoma biopsies revealed that amoeboid melanoma cells with high Myosin II activity are predominant in the invasive fronts of primary tumors in proximity to CD206+CD163+ tumor-associated macrophages and vessels. Proteomic analysis shows that ROCK-Myosin II activity in amoeboid cancer cells controls an immunomodulatory secretome, enabling the recruitment of monocytes and their differentiation into tumor-promoting macrophages. Both amoeboid cancer cells and their associated macrophages support an abnormal vasculature, which ultimately facilitates tumor progression. Mechanistically, amoeboid cancer cells perpetuate their behavior via ROCK-Myosin II-driven IL-1α secretion and NF-κB activation. Using an array of tumor models, we show that high Myosin II activity in tumor cells reprograms the innate immune microenvironment to support tumor growth. We describe an unexpected role for Myosin II dynamics in cancer cells controlling myeloid function via secreted factors.

Exploring major signaling cascades in melanomagenesis: a rationale route for targetted skin cancer therapy

Although most melanoma cases may be treated by surgical intervention upon early diagnosis, a significant portion of patients can still be refractory, presenting low survival rates within 5 years after the discovery of the illness. As a hallmark, melanomas are highly prone to evolve into metastatic sites. Moreover, melanoma tumors are highly resistant to most available drug therapies and their incidence have increased over the years, therefore leading to public health concerns about the development of novel therapies. Therefore, researches are getting deeper in unveiling the mechanisms by which melanoma initiation can be triggered and sustained. In this context, important progress has been achieved regarding the roles and the impact of cellular signaling pathways in melanoma. This knowledge has provided tools for the development of therapies based on the intervention of signal(s) promoted by these cascades. In this review, we summarize the importance of major signaling pathways (mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K)-Akt, Wnt, nuclear factor κ-light-chain-enhancer of activated B cell (NF-κB), Janus kinase (JAK)-signal transducer and activator of transcription (STAT), transforming growth factor β (TGF-β) and Notch) in skin homeostasis and melanoma progression. Available and developing melanoma therapies interfering with these signaling cascades are further discussed.

Targeted Tumor Therapy Remixed-An Update on the Use of Small-Molecule Drugs in Combination Therapies

Over the last decade, the treatment of tumor patients has been revolutionized by the highly successful introduction of novel targeted therapies, in particular small-molecule kinase inhibitors and monoclonal antibodies, as well as by immunotherapies. Depending on the mutational status, BRAF and MEK inhibitor combinations or immune checkpoint inhibitors are current first-line treatments for metastatic melanoma. However, despite great improvements of survival rates limitations due to tumor heterogeneity, primary and acquired therapy resistance, immune evasion, and economical considerations will need to be overcome. Accordingly, ongoing clinical trials explore the individualized use of small-molecule drugs in new targeted therapy combinations based on patient parameters and tumor biopsies. With focus on melanoma therapy this review aims at providing a comprehensive overview of such novel alternative and combinational therapy strategies currently emerging from basic research. The molecular principles and drug classes that may hold promise for improved tumor therapy combination regimens including kinase inhibition, induction of apoptosis, DNA-damage response inhibition, epigenetic reprogramming, telomerase inhibition, redox modulation, metabolic reprogramming, proteasome inhibition, cancer stem cell transdifferentiation, immune cell signaling modulation, and others, are explained in brief. In addition, relevant targeted therapy combinations in current clinical trials and individualized treatment strategies are highlighted.

The combination of MLN2238 (ixazomib) with interferon-alpha results in enhanced cell death in melanoma

The ubiquitin-proteasome signaling pathway is critical for cell cycle regulation and neoplastic growth. Proteasome inhibition can activate apoptotic pathways. Bortezomib, a selective proteasome inhibitor, has anti-melanoma activity. MLN2238 (ixazomib), an oral proteasome inhibitor, has improved pharmacotherapeutic parameters compared to bortezomib. Interferon-alpha (IFN-α), an immune boosting agent, is FDA-approved for treatment of melanoma. In this study in vitro and in vivo evaluation of the antitumor potential of ixazomib and combination treatments with ixazomib and IFN-α were performed. Apoptosis induced by ixazomib was first observed at 12 hours and was maximal at 48 hours with similar levels of cell death compared to bortezomib. IFN-α alone had little effect on cell viability in vitro. However, the combination of ixazomib with IFN-α significantly enhanced ixazomib's ability to induce apoptotic cell death in BRAF V600E mutant and BRAF wild-type human melanoma tumor cells. The combination of ixazomib and IFN-α also enhanced inhibition of cell proliferation in BRAF V600E mutant melanoma tumor cells; however, this was not seen in BRAF wild-type cells. Ixazomib-induced apoptosis was associated with processing of the pro-apoptotic proteins procaspase-3, -7, -8, and -9, and cleavage of poly-ADP-ribose polymerase (PARP). In an in vivo xenograft model of human melanoma, combination treatment with IFN-α-2b and ixazomib demonstrated a significant reduction in tumor volume when compared to vehicle (p = 0.005) and single therapy ixazomib (p = 0.017) and IFN-α-2b (p = 0.036). These pre-clinical results support further evaluation of combination treatment with ixazomib and IFN-α for the treatment of advanced BRAF V600E mutant melanoma.

Molecular mechanisms for synergistic effect of proteasome inhibitors with platinum-based therapy in solid tumors

The successful development of the proteasome inhibitor bortezomib as an anticancer drug has improved survival in patients with multiple myeloma. With the emergence of the newly US Food and Drug Administration-approved proteasome inhibitor carfilzomib, ongoing trials are investigating this compound and other proteasome inhibitors either alone or in combination with other chemotherapy drugs. However, in solid tumors, the efficacy of proteasome inhibitors has not lived up to expectations. Results regarding the potential clinical efficacy of bortezomib combined with other agents in the treatment of solid tumors are eagerly awaited. Recent identification of the molecular mechanisms (involving apoptosis and autophagy) by which bortezomib and cisplatin can overcome chemotherapy resistance and sensitize tumor cells to anticancer therapy can provide insights into the development of novel therapeutic strategies for patients with solid malignancies.

Efficacy of therapy with bortezomib in solid tumors: a review based on 32 clinical trials

The ubiquitin-proteasome system is a major pathway for protein degradation, so that proteasome is now considered as an important target for drug discovery. Bortezomib, the first US FDA-approved proteasome inhibitor now used as a front-line treatment for multiple myeloma. To better understand the effects of bortezomib in cancer treatment, we carried out a review based on 32 published clinical trials to determine whether bortezomib will benefit patients with solid tumors. Information of complete response, partial response, stable disease and objective response rate was collected to assess clinical outcomes. A lack of therapeutic effects was observed when bortezomib was used as a single agent. Meanwhile, when bortezomib treatment was combined with other agents, bortezomib offered no statistically significant response versus these agents alone. High-quality studies are required to better understand the clinically effects of bortezomib and the development of a new generation of proteasome inhibitors is absolutely necessary.

A phase I trial of bortezomib and interferon-α-2b in metastatic melanoma

The possibility that cytokine administration could enhance the antitumor effects of proteasome inhibition was explored. It was found that coadministration of bortezomib and interferon-α (IFN-α) induced synergistic apoptosis in human melanoma cell lines and prolonged survival in a murine model of melanoma. A phase I study was conducted to determine the tolerability and the maximum tolerated dose of bortezomib when administered in combination with IFN-α-2b to patients with metastatic melanoma. Patients were treated on a 5-week cycle. In week 1 of cycle 1, patients received 5 million U/m(2) IFN-α subcutaneously thrice weekly. During weeks 2-4 of cycle 1, bortezomib was administered intravenously weekly along with IFN-α thrice weekly. There was a treatment break during week 5. After cycle 1, bortezomib was administered in combination with IFN-α. Bortezomib was administered in escalating doses (1.0, 1.3, or 1.6 mg/m) to cohorts of 3 patients. Sixteen patients were treated (8 women, 8 men; median age 59 y). Common grade 3 toxicities included fatigue (5), vomiting (3), and diarrhea (3). Grade 4 toxicities included fatigue (3) and lymphopenia (1). The maximum tolerated dose for bortezomib was 1.3 mg/m(2). One patient had a partial response, and 7 had stable disease. Progression-free survival was 2.5 months, and overall survival was 10.3 months. Bortezomib administration did not augment the ability of IFN-α to induce phosphorylation of STAT1 in circulating immune cells; however, it did lead to reduced plasma levels of proangiogenic cytokines. The combination of bortezomib and IFN-α can be safely administered to melanoma patients.

Radiopharmaceutical therapy of patients with metastasized melanoma with the melanin-binding benzamide 131I-BA52

The performance of cytotoxic drugs is defined by their selectivity of uptake and action in tumor tissue. Recent clinical responses achieved by treating metastatic malignant melanoma with therapeutic modalities based on gene expression profiling showed that malignant melanoma is amenable to systemic treatment. However, these responses are not persistent, and complementary targeted treatment strategies are required for malignant melanoma.

METHODS

Here we provide our experience with different labeling procedures for the radioiodination of benzamides and report on initial dosimetry data and the first therapeutic application of (131)I-BA52, a novel melanin-binding benzamide in patients with metastatic malignant melanoma. Twenty-six adults with histologically documented metastasized malignant melanoma received a single dose of 235 ± 62 MBq of (123)I-BA52 for planar and SPECT/CT imaging. Nine patients were selected for radionuclide therapy and received a median of 4 GBq (minimum, 0.51 GBq; maximum, 6.60 GBq) of the β-emitting radiopharmaceutical (131)I-BA52.

RESULTS

A trimethyltin precursor-based synthesis demonstrated high radiochemical yields in the large-scale production of radioiodinated benzamides required for clinical application. (123)I-BA52 showed specific uptake and long-term retention in tumor tissue with low transient uptake in the excretory organs. In tumor tissue, a maximum dose of 12.2 Gy per GBq of (131)I-BA52 was calculated. The highest estimated dose to a normal organ was found for the lung (mean, 3.1 Gy/GBq). No relevant acute or mid-term toxicity was observed with the doses administered until now. Even though dosimetric calculations reveal that the doses applied in this early phase of clinical application can be significantly increased, we observed antitumor effects with follow-up imaging, and single patients of the benzamide-positive cohort of patients (3/5 of the patients receiving a dose > 4.3 GBq) demonstrated a surprisingly long survival of more than 2 y.

CONCLUSION

These data indicate that systemic radionuclide therapy using (131)I-BA52 as a novel approach for the therapy of malignant melanoma is of considerable potential. Future trials should be done to enhance the precision of dosimetry, validate the maximum tolerable dose, and evaluate the effectiveness of the treatment in a prospective manner.

Targeting nuclear factor-kappa B to overcome resistance to chemotherapy

Intrinsic or acquired resistance to chemotherapeutic agents is a common phenomenon and a major challenge in the treatment of cancer patients. Chemoresistance is defined by a complex network of factors including multi-drug resistance proteins, reduced cellular uptake of the drug, enhanced DNA repair, intracellular drug inactivation, and evasion of apoptosis. Pre-clinical models have demonstrated that many chemotherapy drugs, such as platinum-based agents, antracyclines, and taxanes, promote the activation of the NF-κB pathway. NF-κB is a key transcription factor, playing a role in the development and progression of cancer and chemoresistance through the activation of a multitude of mediators including anti-apoptotic genes. Consequently, NF-κB has emerged as a promising anti-cancer target. Here, we describe the role of NF-κB in cancer and in the development of resistance, particularly cisplatin. Additionally, the potential benefits and disadvantages of targeting NF-κB signaling by pharmacological intervention will be addressed.

Metastatic melanoma - a review of current and future drugs

Background:

Melanoma is one of the most aggressive cancers, and it is estimated that 76,250 men and women will be diagnosed with melanoma of the skin in the USA in 2012. Over the last few decades many drugs have been developed but only in 2011 have new drugs demonstrated an impact on survival in metastatic melanoma.

Methods:

A systematic search of literature was conducted, and studies providing data on the effectiveness of current and/or future drugs used in the treatment of metastatic melanoma were selected for review. This review discusses the advantages and limitations of these agents, evaluating past, current and future clinical trials designed to overcome such limitations.

Results:

To date, there are four drugs approved by the Food and Drug Administration for melanoma (dacarbazine, interleukin-2, ipilimumab and vemurafenib). Despite efforts to develop new drugs, few of them have demonstrated any clinical benefits. Approved in 1975, dacarbazine remains the gold standard in chemotherapy, although ipilimumab and vemurafenib have raised many hopes in the last few years. Combining dacarbazine or other chemotherapy agents with new pharmacological agents may be a new way to achieve better clinical responses in patients with metastatic melanoma.

Discussion:

Advances in the molecular knowledge of melanoma have led to major improvements in the treatment of patients with metastatic melanoma, providing new targets and insights. However, heterogeneity amongst study populations, different approaches to treatment and the different melanoma types and localisations included in the trials makes their comparison difficult. New studies focusing on drugs developed in recent decades are warranted.

Mitosis-targeted anti-cancer therapies: where they stand

The strategy of clinically targeting cancerous cells at their most vulnerable state during mitosis has instigated numerous studies into the mitotic cell death (MCD) pathway. As the hallmark of cancer revolves around cell-cycle deregulation, it is not surprising that antimitotic therapies are effective against the abnormal proliferation of transformed cells. Moreover, these antimitotic drugs are also highly selective and sensitive. Despite the robust rate of discovery and the development of mitosis-selective inhibitors, the unpredictable complexities of the human body's response to these drugs still herald the biggest challenge towards clinical success. Undoubtedly, the need to bridge the gap between promising preclinical trials and effective translational bedside treatment prompts further investigations towards mapping out the mechanistic pathways of MCD, understanding how these drugs work as medicine in the body and more comprehensive target validations. In this review, current antimitotic agents are summarized with particular emphasis on the evaluation of their clinical efficacy as well as their limitations. In addition, we discuss the basis behind the lack of activity of these inhibitors in human trials and the potential and future directions of mitotic anticancer strategies.

Is Age ≥ 70 Years an Important Predictor of Adverse Events Among Patients Enrolled in Metastatic Melanoma Trials? Findings from Pooled Analyses of Therapeutic Trials

BACKGROUND: The current study was undertaken to explore whether older age predicts adverse event rates in metastatic melanoma patients participating in cancer clinical trials. METHODS: Six phase II studies conducted at our institution for patients with metastatic disease were used in these pooled analyses: 1) ABT-510; 2) bortezomib, paclitaxel, and carboplatin; 3) everolimus; 4) bevacizumab, paclitaxel, carboplatin; 5) carboplatin and abraxane; and 6) temozolomide and everolimus. In total, 233 patients, 64 elderly (≥ 70 years) and 169 younger, were analyzed for age-based differences in grade 2 or worse adverse events and other clinical outcomes. RESULTS: Despite the fact that older patients had slightly worse performance scores, based on age, no differences in rates of adverse events were observed. Only worse baseline performance score predicted a higher rate of adverse events: patients with performance scores of one or worse were almost 4 times more likely to experience adverse events. Median cancer progression free survival and overall survival were comparable between older and younger patients. CONCLUSION: These findings suggest that concern for adverse event rates should not preclude the enrollment of elderly melanoma patients to cancer clinical trials. Such patients should continue to be monitored carefully for tumor response and toxicity.

NF-κB as potential target in the treatment of melanoma

The RAS/MAP kinase pathway has attracted attention because activating mutations of the BRAF serine/threonine kinase was described in over 50% of melanomas. Very recently, selective and potent BRAF inhibitors have been developed. Several other signal transduction pathways have been found to be constitutively active or mutated in other subsets of melanoma tumors that are potentially targetable with new agents. Among these, NFκB is another pathway that melanoma tumors use to achieve survival, proliferation and resistance to apoptosis. Inhibition of NF-κB activation appears to be a very promising option for anti-cancer therapies.

Prospective analysis of association between use of statins and melanoma risk in the Women's Health Initiative

BACKGROUND

Melanoma is the most lethal form of skin cancer, with an estimated 68,130 new cases and 8700 deaths in the United States in 2010. The increasing incidence and high death rate associated with metastatic disease support the need to focus on prevention. The authors used data from the Women's Health Initiative (WHI) to assess whether 3-hydroxy-3 methylglutaryl coenzyme A inhibitors (statins) are associated with a decreased risk of melanoma.

METHODS

The study population consisted of 119,726 postmenopausal white women, in which 1099 cases of malignant melanoma were identified over an average (± standard deviation) of 11.6 ± 3.2 years. All diagnoses were confirmed by medical record review and pathology reports. Information on statin use was collected at baseline and during follow-up. Self-administered and interview-administered questionnaires were used to collect information on other risk factors. Cox proportional hazards regression was used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs). Analyses investigated the association of any statin use, type, potency, lipophilic status, and duration of use with melanoma.

RESULTS

Statins were used by 8824 women (7.4%) at baseline. The annualized rate of melanoma was 0.09% among statin users and 0.09% among nonusers The multivariable adjusted HR for statin users compared with nonusers was 1.14 (95% CI, 0.91-1.43). There were no significant differences in risk based on statin type, potency, category, duration, or in time-dependent models.

CONCLUSIONS

There was no significant association between statin use and melanoma risk among postmenopausal women in the WHI.

RAS/RAF/MEK/ERK and PI3K/PTEN/AKT Signaling in Malignant Melanoma Progression and Therapy

Cutaneous malignant melanoma is one of the most serious skin cancers and is highly invasive and markedly resistant to conventional therapy. Melanomagenesis is initially triggered by environmental agents including ultraviolet (UV), which induces genetic/epigenetic alterations in the chromosomes of melanocytes. In human melanomas, the RAS/RAF/MEK/ERK (MAPK) and the PI3K/PTEN/AKT (AKT) signaling pathways are two major signaling pathways and are constitutively activated through genetic alterations. Mutations of RAF, RAS, and PTEN contribute to antiapoptosis, abnormal proliferation, angiogenesis, and invasion for melanoma development and progression. To find better approaches to therapies for patients, understanding these MAPK and AKT signaling mechanisms of melanoma development and progression is important. Here, we review MAPK and AKT signaling networks associated with melanoma development and progression.

Resistance to chemotherapy and molecularly targeted therapies: rationale for combination therapy in malignant melanoma

Metastatic melanoma is one of the most intractable tumors, with all current regimens showing limited survival impact. Failure of most agents is attributed to development of therapy resistance. Accumulated evidence points to the apoptotic defect of melanoma cells and the surge of survival signals stimulated by cytotoxic drugs, as a way that tumors circumvent cytotoxic chemotherapy. An overview of inhibitors developed against these growth/survival factors, which are potential partners to be combined with systemic chemotherapy, will be discussed. The escape mechanism from molecular inhibitors also suggests a "vertical" or "horizontal" combination of molecularly targeted therapies. A better understanding of the interactions between simultaneously used regimens and of the rationale for combination therapy will provide new insights to improve survival and quality of life in patients with advanced melanoma.

Rationally designed treatment for solid tumors with MAPK pathway activation: a phase I study of paclitaxel and bortezomib using an adaptive dose-finding approach

In the preclinical setting, phosphorylation and subsequent proteosomal degradation of the proapoptotic protein BIM confers resistance to paclitaxel in solid tumors with RAS/RAF/MAPK pathway activation. Concurrent administration of the proteasome inhibitor bortezomib enables paclitaxel-induced BIM accumulation, restoring cancer cell apoptosis in vitro and producing tumor regression in mice in vivo. A phase I study was conducted to determine the maximum tolerated dose (MTD) of paclitaxel and bortezomib combinatorial treatment. Sixteen patients with refractory solid tumors commonly exhibiting mitogen-activated protein kinase (MAPK) pathway activation were treated weekly with paclitaxel and bortezomib. Starting doses were 40 mg/m(2) for paclitaxel and 0.7 mg/m(2) for bortezomib. A modified continual reassessment method adapted for 2-drug escalation was used for MTD determination with 3-patient cohorts treated at each dose level. MTD was reached at 60 mg/m(2) paclitaxel and 1.0 mg/m(2) bortezomib, the recommended phase II dose. Therapy was overall well tolerated. Most frequently observed toxicities included anemia (in 43.75% of patients, one grade 3 event), fatigue (in 43.75% of patients, one grade 3 event beyond cycle 1), and neuropathy (in 31.25% of patients, one grade 3 event after cycle 1). Of 15 evaluable patients, one non-small-cell lung carcinoma (NSCLC) patient with paclitaxel exposure at the adjuvant setting had a partial response and five patients had stable disease (SD); median disease stabilization was 143.5 days; three NSCLC patients had SD lasting 165 days or longer. Thus, rationally designed weekly treatment with paclitaxel and bortezomib in solid tumors with MAPK pathway activation, including previously taxane-treated malignancies, is a tolerable regimen with preliminary signals of antitumor activity worthy of further investigation.