Current status and future direction in the management of malignant melanoma. Melanoma Res. 2017;27:403-410. [PMID: 28800028 DOI: 10.1097/cmr.0000000000000379]

Prognostic nomograms for predicting long-term overall survival in spindle cell melanoma: a population-based study

Background

There are few research findings on the survival prognosis of spindle cell melanoma (SCM), which is an unusual kind of melanoma. The purpose of this study was to develop a thorough nomogram for predicting the overall survival (OS) of patients with SCM and to assess its validity by comparing it with the conventional American Joint Committee on Cancer (AJCC) staging system.

Methods

The Surveillance, Epidemiology, and End Results database was searched, and 2,015 patients with SCM were selected for the analysis. The patients were randomly divided into training (n = 1,410) and validation (n = 605) cohorts by using R software. Multivariate Cox regression was performed to identify predictive factors. A nomogram was established based on these characteristics to predict OS in SCM. The calibration curve, concordance index (C-index), area under the receiver operating characteristic curve, and decision-curve analysis were utilized to assess the accuracy and reliability of the model. The net reclassification improvement and integrated discrimination improvement were also applied in this model to evaluate its differences with the AJCC model.

Results

The developed nomogram suggests that race, AJCC stage, chemotherapy status, regional node examination status, marital status, and sex have the greatest effects on OS in SCM. The nomogram had a higher C-index than the AJCC staging system (0.751 versus 0.633 in the training cohort and 0.747 versus 0.650 in the validation cohort). Calibration plots illustrated that the model was capable of being calibrated. These criteria demonstrated that the nomogram outperforms the AJCC staging system alone.

Conclusion

The nomogram developed in this study is sufficiently reliable for forecasting the risk and prognosis of SCM, which may facilitate personalized treatment recommendations in upcoming clinical trials.

An injectable nanocomposite hydrogel prevents postoperative tumor recurrence and wound infection via synergistic photothermal-chemo-therapy

HYPOTHESIS

Tumor recurrence, bacterial infection, and wound healing remain significant clinical challenges after skin-tumor resection. In this study, we tested the hypothesis that a multifunctional nanocomposite platform containing nanoparticles (NPs) with the photothermal agent IR820 and bioactive drug curcumin (Cur) would be able to prevent tumor recurrence, limit bacterial wound infections, and promote wound healing.

EXPERIMENTS

In this study, we developed a near-infrared light-activated nanocomposite hydrogel system (Hydrogel/Cur@IR820) by incorporating self-assembled NPs (Cur@IR820) in solutions containing Pluronic F127 modified with aldehyde groups (F127-CHO) and polyethyleneimine-grafted F127 (F127-PEI).

FINDINGS

The Hydrogel/Cur@IR820 platform exhibited inherent multifunctional properties, including superior injectability, self-healing behavior, photothermal effects, and free radical scavenging ability. The Cur@IR820 NPs led to photonic hyperthermia and near-infrared (NIR)-triggered Cur release, which drove synergistic therapeutic effects against bacteria and tumor cells. Furthermore, the Hydrogel/Cur@IR820 system promoted wound repair and tissue regeneration by reducing inflammation through the antioxidant properties of Cur. Overall, the results of this study have clinical implications for inhibiting tumor growth, treating bacterial infections, and accelerating tissue regeneration.

Glucose oxidase and ruthenium nanorods-embedded self-healing polyvinyl alcohol/polyethylene imine hydrogel for simultaneous photothermal/photodynamic/starvation therapy and skin reconstruction

Tumor recurrence and wound healing represent significant burdens for tumor patients after the surgical removal of melanomas. Wound dressings with wound healing and anticancer therapeutic abilities could help to solve these issues. Thus, a hybrid hydrogel made of polyvinyl alcohol (PVA) and polyethylene imine (PEI) was prepared by cross-linking imine bond and boronic acid bond. This hydrogel was loaded with ruthenium nanorods (Ru NRs) and glucose oxidase (GOx) and named as nanocomposite hydrogel (Ru/GOx@Hydrogel), exhibiting remarkable photothermal/photodynamic/starvation antitumor therapy and wound repair abilities. Ru NRs are bifunctional phototherapeutic agents that simultaneously exhibit intrinsic photothermal and photodynamic functions. Three-dimensional composite hydrogel loaded with GOx can also consume glucose in the presence of O2 during tumor starvation therapy. Near-infrared (NIR) light-triggered hyperthermia can not only promote the consumption of glucose, but also facilitate the ablation of residual cancer cells. The antitumor effect of the Ru/GOx@Hydrogel resulted in significant improvements, compared to those observed with either phototherapy or starvation therapy alone. Additionally, the postoperative wound was substantially healed after treatment with Ru/GOx@Hydrogel and NIR irradiation. Therefore, the Ru/GOx@Hydrogel can be used as a multi-stimulus-responsive nanoplatform that could facilitate on-demand controlled drug release, and be used as a promising postoperative adjuvant in combination therapy.

A novel mitochondria-targeting compound exerts therapeutic effects against melanoma by inducing mitochondria-mediated apoptosis and autophagy in vitro and in vivo

Melanoma is the most invasive skin cancer, with a high mortality rate. However, existing therapeutic drugs have side effects, low reactivity, and lead to drug resistance. As the power source in cells, mitochondria play an important role in the survival of cancer cells and are an important target for tumor therapy. This study aimed to develop a new anti-melanoma compound that targets mitochondria, evaluate its effect on the proliferation and metastasis of melanoma cells, and explore its mechanism of action. The novel mitochondria-targeting compound, SCZ0148, was synthesized by modifying the structure of cyanine. Then, A375 and B16 cells were incubated with different concentrations of SCZ0148, and different doses of SCZ0148 were administered to A375 and B16 xenograft zebrafish. The results showed that SCZ0148 targeted mitochondria, had dose- and time-dependent effects on the proliferation of melanoma cell lines, and had no obvious side effects on normal cells. In addition, SCZ0148 induced melanoma cell apoptosis through the reactive oxygen species-mediated mitochondrial pathway of apoptosis and promoted autophagy. SCZ0148 significantly inhibited the migration of melanoma cells via a matrix metalloprotein 9-mediated pathway. Similarly, SCZ0148 inhibited melanoma cell proliferation in a concentration-dependent manner in vivo. In summary, SCZ0148 may be a novel anti-melanoma compound that targets mitochondria.

Evaluation of the therapeutic efficacy of 213Bi-labelled DOTA-conjugated alpha-melanocyte stimulating hormone peptide analogues in melanocortin-1 receptor positive preclinical melanoma model

Melanocortin-1 receptor (MC1-R) targeting alpha-melanocyte stimulating hormone-analogue (α-MSH) biomolecules labelled with α-emitting radiometal seem to be valuable in the targeted radionuclide therapy of MC1-R positive melanoma malignum (MM). Herein is reported the anti-tumor in vivo therapeutic evaluation of MC1-R-affine [213Bi]Bi-DOTA-NAPamide and HOLDamide treatment in MC1-R positive B16-F10 melanoma tumor-bearing C57BL/6J mice. On the 6th, 8th and 10th days post tumor cell inoculation; the treated groups of mice were intravenously injected with approximately 5 MBq of both amide derivatives. Beyond body weight and tumor volume assessment, [68Ga]Ga-DOTA-HOLDamide and NAPamide-based PET/MRI scans, and ex vivo biodistribution studies were executed 30,- and 90 min postinjection. In the PET/MRI imaging studies the B16-F10 tumors were clearly visualized with both 68Ga-labelled tracers, however, significantly lower tumor-to-muscle (T/M) ratios were observed by using [68Ga]Ga-DOTA-HOLDamide. After alpha-radiotherapy treatment the tumor size of the control group was larger relative to both treated cohorts, while the smallest tumor volumes were observed in the NAPamide-treated subclass on the 10th day. Relatively higher [213Bi]Bi-DOTA-NAPamide accumulation in the B16-F10 tumors (%ID/g: 2.71 ± 0.15) with discrete background activity led to excellent T/M ratios, particularly 90 min postinjection. Overall, the therapeutic application of receptor selective [213Bi]Bi-DOTA-NAPamide seems to be feasible in MC1-R positive MM management.

Nanosonosensitizers-engineered injectable thermogel for augmented chemo-sonodynamic therapy of melanoma and infected wound healing

Easy recurrence and bacteria infected-wound healing after surgery excision pose severe challenges to clinical melanoma therapy. Herein, an injectable CuO₂ nanodots-engineered thermosensitive chitosan hydrogel (CuO₂-BSO@Gel) for enhanced melanoma chemo-sonodynamic therapy and improved infected wound healing was rationally constructed by facilely integrating the CuO₂ nanodots and L-Buthionine-(S, R)-sulfoximine (BSO) with thermoresponsive hydrogel. Favored by the Fenton catalytic activity of Cu²⁺, the CuO₂ nanodots can achieve enhanced chemodynamic therapy (CDT) by self-supplying H₂O₂ under acidic tumor microenvironment. Simultaneously, the CuO₂ nanodots with a narrow bandgap (2.29 ​eV) were proven to be the efficient sonosensitizers, and the corresponding quantum yield of singlet oxygen (¹O₂) could be boosted by the O₂ generation during Fenton-like reactions. Additionally, combining with the glutathione (GSH) depletion of loaded BSO, intracellular oxidative stress induced by SDT and CDT was further amplified, leading to the specific ferroptosis. Importantly, this multifunctional hydrogel significantly promoted the proliferation of normal skin cells and accelerated the bacteria-infected wound healing by the effective chemo-sonodynamic antibacterial activity and the enhanced angiogenesis. Thus, the engineered thermogel features the distinct chemo-sonodynamic performance, desirable biocompatibility and bioactivity, providing a competitive strategy for eradicating melanoma and infected wound healing.

A copper-metal organic framework enhances the photothermal and chemodynamic properties of polydopamine for melanoma therapy

The combination of photothermal treatment and chemodynamic therapy has attracted extensive attention for improving therapeutic effects and compensating the insufficiency of monotherapy. In this work, a copper-metal organic framework (Cu-BTC) was used to augment the photothermal effect of polydopamine (PDA) and endow it with a chemodynamic ability by constructing a Cu-BTC@PDA nanocomposite. Density functional theory calculations revealed that the plasmonic vibrations formed by the d-d transition of Cu at the Fermi level in Cu-BTC@PDA could enhance the photothermal performance of PDA. In addition, more Cu²⁺ released from Cu-BTC@PDA in the acidic microenvironment of the tumor was then reduced to Cu⁺ by glutathione (GSH) and further catalyzed H₂O₂ to generate more toxic hydroxyl radical (•OH), which synergized with photothermal treatment for melanoma therapy. Furthermore, Cu-BTC@PDA could quickly and effectively kill bacteria under the action of PTT, and the sustained release of Cu ions could contribute to the long-term and stable bacteriostatic ability of the material. This sustained release of Cu ions could also promote the cell migration and angiogenesis, and upregulate the expression of COL-, TGF-, and VEGF-related genes to accelerate wound healing. This multifunctional nanomaterial has potential application in the treatment of melanoma and repair of wounds. STATEMENT OF SIGNIFICANCE: We constructed a multifunctional nanoplatform (Cu-BTC@PDA) by two steps. This nanoplatform can not only perform cascade catalysis in the tumor microenvironment to generate more toxic hydroxyl radical (•OH), but also synergize with photothermal treatment for melanoma therapy. Additionally, Cu-BTC@PDA possesses enhanced photothermal performance through the plasmonic vibrations formed by the d-d transition of Cu at the Fermi level in Cu-BTC@PDA, which is revealed by DFT calculations. And Cu-BTC@PDA shows good antitumor, antibacterial, and wound healing properties in vivo and in vitro. Such a multifunctional nanomaterial has potential application in the treatment of melanoma and repair of wounds.

Basic Fibroblast Growth Factor Blockade Leads to Distinct Cellular Responses in Melanoma B16 Cells

Although bFGF is highly expressed in the melanoma tissues, its specific role in melanoma progression is still not completely clarified. Here, we investigated the consequent cellular responses in melanoma B16 cells after bFGF blocking by using a neutralizing monoclonal antibody (mAb). Results showed that bFGF mAb concentration dependent inhibited tumor cell growth. Meanwhile, cell viability suppression was accompanied by reduced levels of proangiogenic factors in low-concentration bFGF mAb-treated cancer cells and increased levels of proangiogenic factors in high-concentration bFGF mAb-treated cells. Furthermore, low-concentration bFGF mAb induced autophagy but not apoptosis; conversely, high-concentration bFGF mAb led to activation of autophagy and apoptosis. Finally, we found that different degrees of bFGF blockade-induced autophagy play distinct roles in promoting cell survival and cell death. Our findings revealed different adaptive responses to bFGF blockade in melanoma cells, which should be taken seriously when developing bFGF-targeting agents for melanoma treatment.

Polydopamine-doped supramolecular chiral hydrogels for postoperative tumor recurrence inhibition and simultaneously enhanced wound repair

Cancer recurrence remains a major challenge after primary tumor excision, and the inflammation of tumor-caused wounds can hinder wound healing and potentially promote tumor growth. Herein, a chiral L-phenylalanine-based (LPFEG) supramolecular hydrogel system encapsulated with polydopamine nanoparticles (PDA-NPs) has been developed in order to prevent tumor relapse after surgery and promote wound repair. PDA-NPs allow for near-infrared (NIR) light-triggered photothermal therapy, especially, it can scavenge free radicals in the surgical wound. LPFEG can mimic native extracellular matrix (ECM) structure to create a chiral microenvironment that enhances fibroblast adhesion, proliferation, and new tissue regeneration. With anticancer drug doxorubicin (DOX) loaded into the composite hydrogel, the antitumor effect is significantly enhanced by the integration of chemo-photothermal therapy both in vitro and in vivo. The PDA-based chiral supramolecular composite hydrogel as an effective postoperative adjuvant possesses promising applicable prospects in inhibiting tumor recurrence and accelerating wound healing after operation. STATEMENT OF SIGNIFICANCE: After primary tumor excision, cancer recurrence remains a severe concern, and the inflammation induced by tumor-related wounds can delay wound healing. Herein, we designed a chiral L-phenylalanine-based (LPFEG) supramolecular hydrogel platform that was co-assembled with polydopamine nanoparticles (PDA-NPs). Among them, PDA-NPs can offer photothermal therapy and scavenge free radicals in surgical wounds. LPFEG can create a chiral microenvironment that promotes fibroblast adhesion, proliferation, and new tissue regeneration. Furthermore, with anticancer drug doxorubicin (DOX) loaded into the composite hydrogel, the antitumor effect is considerably boosted. Therefore, the PDA-based chiral supramolecular hydrogel shows high application potential as a postoperative adjuvant in preventing tumor relapse as well as accelerating wound healing after surgery.

Intramedullary Spinal Cord Metastasis as Initial Presentation of Malignant Melanoma: A Unique Case Report and Role of Contrast vs Non-contrast MRI in Its Diagnosis

Intramedullary spinal cord metastasis (ISCM) is a diagnostically challenging and dreadful complication of cancer. Twenty-seven cases of ISCM exclusively related to malignant melanoma have been reported so far in a recent study.On review of literature, we could not find any reported case with ISCM secondary to malignant melanoma as initial presentation. To the best of our knowledge, we are reporting the first such case. We report a case of a 71-year-old lady presenting with gradual onset of bilateral leg weakness “off legs” and lower limb paresthesias. On examination she had an upper motor neuron pattern lower limb weakness with reduced sensations to all modalities and brisk reflexes with extensor plantar responses. She was evaluated with non-contrast MRI (magnetic resonance imaging) spine which showed focal myelopathic cord signal at the conus and at the level of T10 and T11 vertebrae (radiological differential diagnosis given on MRI were B12 deficiency/inflammatory/infection). Thorough radiological scans were ordered which revealed a disseminated malignancy. A biopsy sample from gastric lesion revealed diagnosis of malignant melanoma. A repeat MRI whole spine with gadolinium contrast was done later with suspicion of spinal metastasis which has led to lower limb weakness. MRI with contrast showed an enhancing soft tissue metastatic mass lesion within conus in comparison with plain MRI done one week earlier. At present, diagnostic modalities available for diagnosing ISCM particularly secondary to melanoma do not have high specificity. Contrast MRI is the diagnostic modality of choice at present. Non-contrast MRI has low sensitivity in diagnosis of ISCM compared to contrast MRI and could potentially delay the management, especially in highly aggressive malignancies like malignant melanoma where an early diagnosis and treatment is critical for better outcome.

Formulation and Evaluation of Resveratrol Loaded Cubosomal Nanoformulation for Topical Delivery

AIM

The aim of the study was to formulate, characterize, and evaluate the Resveratrol- loaded Cubosomes (RC) for topical application.

BACKGROUND

Resveratrol (RV) is a nutraceutical compound with exciting pharmacological potential in different diseases, including cancers. Many studies on resveratrol have been reported for anti- melanoma activity. Due to its low bioavailability, the therapeutic activities of resveratrol are strongly limited. Hence, an approach with nanotechnology has been made to increase its activity through transdermal drug delivery.

OBJECTIVE

To formulate, characterize, and evaluate the resveratrol-loaded cubosomes (RC). To evaluate Resveratrol-loaded Cubosomal Gel (RC-Gel) for its topical application.

METHODS

RC was formulated by homogenization technique and optimized using a 2-factor 3-level factorial design. Formulated RCs were characterized for particle size, zeta potential, and entrapment efficiency. Optimized RC was evaluated for in vitro release and stability study. Optimized RC was further formulated into cubosomal gel (RC-Gel) using carbopol and evaluated for drug permeation and deposition. Furthermore, developed RC-Gel was evaluated for its topical application using skin irritancy, toxicity, and in vivo local bioavailability studies.

RESULTS

The optimized RC indicated cubic-shaped structure with mean particle size, entrapment efficiency, and zeta potential were 113±2.36 nm, 85.07 ± 0.91%, and -27.40 ± 1.40 mV, respectively. In vitro drug release of optimized RC demonstrated biphasic drug release with the diffusion-controlled release of resveratrol (RV) (87.20 ± 3.91%). The RC-Gel demonstrated better drug permeation and deposition in mice skin layers. The composition of RC-Gel has been proved non-irritant to mice skin. In vivo local bioavailability study depicted the good potential of RC-Gel for skin localization.

CONCLUSION

The RC nanoformulation proposes a promising drug delivery system for melanoma treatment simply through topical application.

Cytotoxic Effect of Iris germanica L. Rhizomes Extract on Human Melanoma Cell Line

Background: Melanoma is the leading cause of 80% of skin cancer worldwide due to its high proliferation rate, metastatic nature, and limited effective therapies. Given the rapid increase in its incidence compared to other skin cancers, new therapeutic agents are needed to control the disease. Scientists are interested in medicinal plants due to their anticancer properties. The rhizomes of the Iris germanica L., known as “Irsa”, is one of the herbs used in traditional Persian medicine for the treatment of various skin cancers. Objectives: This study aimed at investigating the cytotoxic effects of Iris germanica on A375 melanoma and AGO-1522 normal human fibroblast cell lines for the first time. Methods: The ethanolic extract was prepared by the maceration method. Cell viability and cytotoxic activities were assessed through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometric assay, using annexin V/propidium iodide (PI) staining. Results: IC50 values were estimated for the A375 melanoma and the AGO-1522 normal cell lines. We revealed that the IC50 for the A375 melanoma was 0.0438 mg/mL and for the AGO-1522 normal cell line was 0.8494 mg/mL after 48 hours of treatment. Furthermore, flow cytometry analysis illustrated that 0.125 mg/mL of the Iris germanica extract could lead to 55.24% apoptosis of the A375 melanoma cell line. The same concentration of the Iris germanica extracts only lead to 8.76% apoptosis in the AGO-1522 cell line. Conclusions: Iris germanica extract has considerable cytotoxic effects on the human melanoma cell line. Further studies are required to demonstrate the therapeutic effects of Iris germanica on melanoma cancer.

Cytoskeletal tubulin competes with actin to increase deformability of metastatic melanoma cells

The formation of membrane protrusions during migration is reliant upon the cells' cytoskeletal structure and stiffness. It has been reported that actin disruption blocks protrusion and decreases cell stiffness whereas microtubule disruption blocks protrusion but increases stiffness in several cell types. In melanoma, cell migration is of concern as this cancer spreads unusually rapidly during early tumour development. The aim of this study was to characterise motility, structural properties and stiffness of human melanoma cells at radial growth phase (RGP), vertical growth phase (VGP), and metastatic stage (MET) in two-dimensional in vitro environments. Wound assays, western blotting and mitochondrial particle tracking were used to assess cell migration, cytoskeletal content and intracellular fluidity. Our results indicate that cell motility increase with increasing disease stage. Despite their different motility, RGP and VGP cells exhibit similar fluidity, actin and tubulin levels. MET cells, however, display increased fluidity which was associated with increased actin and tubulin content. Our findings demonstrate an interplay between actin and microtubule activity and their role in increasing motility of cells while minimizing cell stiffness at advanced disease stage. In earlier disease stages, cell stiffness may however not serve as an indicator of migratory capabilities.

RNAi-mediated IARS2 knockdown inhibits proliferation and promotes apoptosis in human melanoma A375 cells

IARS2, which encodes the mitochondrial form of isoleucyl-tRNA synthetase, has been found to play an important role in a range of diseases, including cancer. However, the relationship between IARS2 and melanoma is still unclear. To evaluate the role of IARS2 in melanoma, we constructed a stable A375 cell line with IARS2 knockdown via lentivirus-mediated small interfering RNAs. The expression of IARS2 was measured by real time-quantitative Polymerase Chain Reaction and western blot analysis. Cell counting, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and colony formation assay were conducted to assess the effect of IARS2 on melanoma cell proliferation. Flow cytometry assay was used to determine cell apoptosis and cell cycle distribution in melanoma A375 cells. Finally, immunohistochemistry was employed to validate the expression of IARS2 protein in melanoma tissues. In this study it was found that IARS2 was highly expressed in melanoma cell lines. Furthermore, IARS2 protein also exhibited elevated expression in the tumour tissues obtained from melanoma patients. After suppression of the mRNA expression of IARS2, the proliferation and colony formation ability of the A375 cells were significantly inhibited, while the proportion of apoptotic A375 cells increased significantly, as indicated by an enhanced phosphatidylserine externalization and caspase 3/7 activity after IARS2 knockdown. Further investigations found that knockdown of IARS2 arrested cells in the G1 phase. The results suggested that IARS2 is critical for proliferation and apoptosis of melanoma cells.

ROS-boosted photodynamic therapy against metastatic melanoma by inhibiting the activity of antioxidase and oxygen-producing nano-dopants

The antioxidant effect weakens the ability of PDT to resist melanoma, and the hypoxic tumor environment further restricts the application of photosensitizers in tumors. Therefore, to enhance the ability of PDT to resist melanoma, we designed a sequential enhanced PDT theranostic platform (Au@MTM-HA). Firstly, the nanotherapeutic platform uses TiO₂ as a photosensitizer, which is doped with MnO₂ to form a mesoporous MTM. The MTM can continuously provide oxygen, thereby increasing the level of reactive oxygen species (ROS) and reducing the metastatic effect by alleviating tumor hypoxia. Furthermore, the released Au₂₅Sv₉ could inhibit the activity of antioxidant defense enzymes and reduce the scavenging of ROS and further enhance the PDT effect. Simultaneously, surface-modified HA could not only recognize CD44 receptor but also act as a sealing agent for carriers. Result: Au@MTM-HA could explosively produce a 3-fold higher ROS and improve the PDT effect. Therefore, this work may provide strong evidence for Au@MTM-HA as a new and promising PDT candidate for the treatment of metastatic melanoma.

Inhibitory effect of kaempferol on mouse melanoma cell line B16 in vivo and in vitro

Introduction

Melanoma is a malignant tumour and is the leading cause of death in patients with skin tumours.

Aim

Kaempferol belongs to a class of flavonoids, and is associated with many biological functions such as anti-inflammatory, anti-oxidation and anti-cancer. However, the inhibitory effect of kaempferol on melanoma still remains unclear.

Material and methods

The effect of kaempferol on melanoma was determined by conducting both in vitro and in vivo experiments using MTT assay and flow cytometry.

Results

The in vitro results revealed that kaempferol obviously inhibited cell viability of melanoma B16 cells, induced cell cycle arrest and cell apoptosis. The in vivo results showed that kaempferol effectively inhibited the growth of mice xenografts. More importantly, kaempferol down-regulated the number of MDSC cells and up-regulated the number of NKT cells and CD8 T cells in the spleen.

Conclusions

Taken together, these findings indicate that kaempferol might play an inhibitory role in the growth of melanoma by enhancing anti-tumour immunity of organisms.

The programmed cell death protein-1/programmed cell death ligand 1 expression, CD3+ T cell infiltration, NY-ESO-1 expression, and microsatellite instability phenotype in primary cutaneous melanoma and mucosal melanoma and their clinical significance and prognostic value: a study of 89 consecutive cases

We evaluated the expression of programmed cell death protein-1 (PD-1), programmed cell death ligand 1 (PD-L1), and NY-ESO-1 antigen; the infiltration of CD3+ T cells; and the microsatellite instability (MSI) phenotype, as well as the relationship of each factor to survival in malignant melanoma patients. Malignant melanoma samples from 89 patients were stained by immunohistochemistry to evaluate PD-1, PD-L1, CD3+ tumor-infiltrating lymphocytes (TILs), NY-ESO-1, and MSI. PD-1 and PD-L1 were expressed in 19.1 and 32.6% of the 89 samples, respectively. There was a significant correlation between PD-1 and PD-L1 expression (r = 0.207, P = 0.046). High infiltration of CD3+ T cells was observed in 41.6% of the samples, and increased cell infiltration was associated with increased PD-1 expression (P = 0.001). NY-ESO-1 antigen was detected in 13.5% of all samples, and the expression of NY-ESO-1 was positively correlated with the expression of PD-1 (P < 0.001). In our research, MSI was detected in 18 samples (20.2%). Survival analysis showed that a high infiltration of CD3+ T cells was related to longer progression-free survival (PFS) [24.0 months, 95% confidence interval (CI): 7.4-40.6 vs. 11.0 months, 95% CI: 7.1-12.9, P = 0.031], similarly, the median overall survival (OS) of the CD3+ T cell high-infiltration patients was also longer (53.0 vs. 38.0 months), but with no statistical significance (P = 0.200). The results for the immune markers mentioned above provide a theoretical basis for the prognosis and immunotherapy selection of malignant melanoma patients.

Precision medicine for gastrointestinal cancer: Recent progress and future perspective

Gastrointestinal (GI) cancer has a high tumor incidence and mortality rate worldwide. Despite significant improvements in radiotherapy, chemotherapy, and targeted therapy for GI cancer over the last decade, GI cancer is characterized by high recurrence rates and a dismal prognosis. There is an urgent need for new diagnostic and therapeutic approaches. Recent technological advances and the accumulation of clinical data are moving toward the use of precision medicine in GI cancer. Here we review the application and status of precision medicine in GI cancer. Analyses of liquid biopsy specimens provide comprehensive real-time data of the tumor-associated changes in an individual GI cancer patient with malignancy. With the introduction of gene panels including next-generation sequencing, it has become possible to identify a variety of mutations and genetic biomarkers in GI cancer. Although the genomic aberration of GI cancer is apparently less actionable compared to other solid tumors, novel informative analyses derived from comprehensive gene profiling may lead to the discovery of precise molecular targeted drugs. These progressions will make it feasible to incorporate clinical, genome-based, and phenotype-based diagnostic and therapeutic approaches and apply them to individual GI cancer patients for precision medicine.

Significance of 5-S-Cysteinyldopa as a Marker for Melanoma

Melanoma is one of the most lethal and malignant cancers and its incidence is increasing worldwide, and Japan is not an exception. Although there are numerous therapeutic options for melanoma, the prognosis is still poor once it has metastasized. The main concern after removal of a primary melanoma is whether it has metastasized, and early detection of metastatic melanoma would be effective in improving the prognosis of patients. Thus, it is very important to identify reliable methods to detect metastases as early as possible. Although many prognostic biomarkers (mainly for metastases) of melanoma have been reported, there are very few effective for an early diagnosis. Serum and urinary biomarkers for melanoma diagnosis have especially received great interest because of the relative ease of sample collection and handling. Several serum and urinary biomarkers appear to have significant potential both as prognostic indicators and as targets for future therapeutic methods, but still there are no efficient serum and urinary biomarkers for early detection, accurate diagnosis and prognosis, efficient monitoring of the disease and reliable prediction of survival and recurrence. Levels of 5-S-cysteinyldopa (5SCD) in the serum or urine as biomarkers of melanoma have been found to be significantly elevated earlier and to reflect melanoma progression better than physical examinations, laboratory tests and imaging techniques, such as scintigraphy and echography. With recent developments in the treatment of melanoma, studies reporting combinations of 5SCD levels and new applications for the treatment of melanoma are gradually increasing. This review summarizes the usefulness of 5SCD, the most widely used and well-known melanoma marker in the serum and urine, compares 5SCD and other useful markers, and finally its application to other fields.

Overexpression of RACK1 Predicts Poor Prognosis in Melanoma

Melanoma is a highly malignant skin cancer with limited treatment options, the mechanism of the occurrence and development of melanoma is still unclear till now. Receptor for activated C kinase 1 (RACK1) is a scaffolding protein that mediates multiple signaling pathways; it interconnects distinct signaling pathways to control essential cellular processes. RACK1 was reported as an oncogene in human tumorigenesis, but little is known about its role in melanoma. This study aimed to investigate the expression of RACK1 in patients with melanoma and to reveal its possible functions in melanoma cells. The expression profiles of RACK1 detected in tumor tissues from melanoma patients showed that RACK1 was higher in tumor tissues, and its expression level was well associated with the clinical progression of melanoma (TNM stage, P=0.009). Furthermore, RNA interfering (RNAi) knockdown of RACK1 could efficiently suppress the proliferation, migration and invasion of A375 and A875 cells and promote their apoptosis. Taken together, these results suggest that RACK1 may be a poor prognostic factor in human melanoma, and it may be a new therapeutic target for melanoma treatment.

miR-124 Functions As A Melanoma Tumor Suppressor By Targeting RACK1

Background

miRNAs are small noncoding RNAs that function as posttranscriptional regulators during development and disease. Aberrant expression of miRNAs has been associated with various types of malignant tumors. Decreased levels of miR-124 have been observed in human cancers. RACK1 is a scaffold protein that acts as an oncogene in various human cancers. The association between miR-124 and RACK1 in melanoma has not been characterized.

Materials and methods

Real-time quantitative PCR was used to analyze RACK1 and miR-124 expression in melanoma tissue and cell lines. Dual-Luciferase reporter assay was performed to evaluate the effect of miR-124 inhibition on RACK1 expression. The effects of miR-124 on RACK1 in melanoma cell lines were evaluated using Western blot analysis and immunocytochemical staining. Wound-healing, transwell, and MTT assays, and annexin V-fluorescein isothiocyanate/propidium iodide followed by flow cytometry were used to evaluate the effects of miR-124 on RACK1-mediated proliferation, migration, invasion, and apoptosis of melanoma cells.

Results

The expression of miR-124 in melanoma tissue was lower than that in normal skin tissue, and the expression of RACK1 was higher in melanoma tissue than that in normal skin tissue. Analysis using Dual-Luciferase reporter assay showed that RACK1 was a direct target of miR-124. Western blot and immunocytochemical staining showed that the expression of RACK1 was significantly inhibited by miR-124 in both A375 and A875 melanoma cells. Furthermore, the results of functional experiments showed that degradation of RACK1 by miR-124 inhibited proliferation, migration, and invasion of melanoma cells, and promoted melanoma cell apoptosis.

Conclusion

The results suggested that miR-124 affected melanoma cells by directly targeting RACK1. miR-124 and RACK1 may be biomarkers for clinical diagnosis, and prognostic factors of human melanoma. Furthermore, miR-124 and RACK1 may be targets for the treatment of melanoma.

Increasing molar activity by HPLC purification improves 68Ga-DOTA-NAPamide tumor accumulation in a B16/F1 melanoma xenograft model

Purpose

Melanocortin receptor 1 (MC1R) is overexpressed in melanoma and may be a molecular target for imaging and peptide receptor radionuclide therapy. ⁶⁸Gallium (⁶⁸Ga) labeling of DOTA-conjugated peptides is an established procedure in the clinic for use in positron emission tomography (PET) imaging. Aim of this study was to compare a standard labeling protocol against the ⁶⁸Ga-DOTA peptide purified from the excess of unlabeled peptide.

Procedures

The MC1R ligand DOTA-NAPamide was labeled with ⁶⁸Ga using a standard clinical protocol. Radioactive peptide was separated from the excess of unlabeled DOTA-NAPamide by HPLC. Immediately after the incubation of peptide and ⁶⁸Ga (95°C, 15 min), the reaction was loaded on a C18 column and separated by a water/acetonitrile gradient, allowing fractionation in less than 20 minutes. Radiolabeled products were compared in biodistribution studies and PET imaging using nude mice bearing MC1R-expressing B16/F1 xenograft tumors.

Results

In biodistribution studies, non-purified ⁶⁸Ga-DOTA-NAPamide did not show significant uptake in the tumor at 1 h post injection (0.78% IA/g). By the additional HPLC step, the molar activity was raised around 10,000-fold by completely removing unlabeled peptide. Application of this rapid purification strategy led to a more than 8-fold increase in tumor uptake (7.0% IA/g). The addition of various amounts of unlabeled DOTA-NAPamide to the purified product led to a blocking effect and decreased specific tumor uptake, similar to the result seen with non-purified radiopeptide. PET imaging was performed using the same tracer preparations. Purified ⁶⁸Ga-DOTA-NAPamide, in comparison, showed superior tumor uptake.

Conclusions

We demonstrated that chromatographic separation of radiolabeled from excess unlabeled peptide is technically feasible and beneficial, even for short-lived isotopes such as ⁶⁸Ga. Unlabeled peptide molecules compete with receptor binding sites in the target tissue. Purification of the radiopeptide therefore improved tumor uptake.

Specific Urinary Metabolites in Malignant Melanoma

Background and objectives: Melanin, which has a confirmed role in melanoma cell behaviour, is formed in the process of melanogenesis and is synthesized from tryptophan, L-tyrosine and their metabolites. All these metabolites are easily detectable by chromatography in urine. Materials and Methods: Urine samples of 133 individuals (82 malignant melanoma patients and 51 healthy controls) were analysed by reversed-phase high-performance liquid chromatography (RP-HPLC). The diagnosis of malignant melanoma was confirmed histologically. Results: Chromatograms of melanoma patients showed increased levels of 5,6-dihydroxyindole-2-carboxylic acid, vanilmandelic acid, homovanilic acid, tryptophan, 5-hydroxyindole-3-acetic acid, and indoxyl sulphate compared to healthy controls. Concentration of indoxyl sulphate, homovanilic acid and tryptophan were significantly increased even in the low clinical stage 0 of the disease (indoxyl sulphate, homovanilic acid and tryptophan in patients with clinical stage 0 vs. controls expressed as medium/ interquartile range in µmol/mmol creatinine: 28.37/15.30 vs. 5.00/6.91; 47.97/33.08 vs. 7.33/21.25; and 16.38/15.98 vs. 3.46/6.22, respectively). Conclusions: HPLC detection of metabolites of L-tyrosine and tryptophan in the urine of melanoma patients may play a significant role in diagnostics as well as a therapeutic strategy of melanoma cancer.

Grape Seed-Inspired Smart Hydrogel Scaffolds for Melanoma Therapy and Wound Healing

Grape-seed extracts contain rich flavonoids with oligomeric proanthocyanidins (OPC). In this study, OPC containing hydrogel scaffolds can function as a natural photothermal agent for melanoma therapy and bioactive biomaterial for wound healing. Inspired by grape-seed extracts, OPC were explored as a photothermal agent and endowed the hydrogel scaffolds with excellent and controlled photothermal ability. The rheological property of the hydrogel scaffolds responded to irradiation time of near infrared (NIR) laser, and OPC contents. The compressive mechanical property of the hydrogel scaffolds was well modulated by NIR laser irradiation with different impact durations. The controlled high temperature induced by OPC-containing hydrogel scaffolds under NIR laser irradiation could effectively kill melanoma cells and suppress tumor growth. In addition, OPC-containing hydrogel scaffolds supported the proliferation and migration of human dermal fibroblasts and human umbilical vein endothelial cells, as well as obviously promoted angiogenesis and skin regeneration in both tumor-caused and chronic wounds. Therefore, OPC-containing hydrogel scaffolds possessed controlled photothermal, rheological, and compressive mechanical properties under NIR laser stimuli, as well as excellent biocompatibility and bioactivity for melanoma therapy and wound healing.

Tyrosinase-Loaded Multicompartment Microreactor toward Melanoma Depletion

Melanoma is malignant skin cancer occurring with increasing prevalence with no effective treatment. A unique feature of melanoma cells is that they require higher concentrations of ltyrosine (l-tyr) for expansion than normal cells. As such, it has been demonstrated that dietary l-tyr restriction lowers systemic l-tyr and suppresses melanoma advancement in mice. Unfortunately, this diet is not well tolerated by humans. An alternative approach to impede melanoma progression will be to administer the enzyme tyrosinase (TYR), which converts l-tyr into melanin. Herein, a multicompartment carrier consisting of a polymer shell entrapping thousands of liposomes is employed to act as a microreactor depleting l-tyr in the presence of melanoma cells. It is shown that the TYR enzyme can be incorporated within the liposomal subunits with preserved catalytic activity. Aiming to mimic the dynamic environment at the tumor site, l-tyr conversion is conducted by co-culturing melanoma cells and microreactors in a microfluidic setup with applied intratumor shear stress. It is demonstrated that the microreactors are concurrently depleting l-tyr, which translates into inhibited melanoma cell growth. Thus, the first microreactor where the depletion of a substrate translates into antitumor properties in vitro is reported.

Cutaneous pH landscape as a facilitator of melanoma initiation and progression

Melanoma incidence is on the rise and currently causes the majority of skin cancer-related deaths. Yet, therapies for metastatic melanoma are still insufficient so that new concepts are essential. Malignant transformation of melanocytes and melanoma progression are intimately linked to the cutaneous pH landscape and its dysregulation in tumour lesions. The pH landscape of normal skin is characterized by a large pH gradient of up to 3 pH units between surface and dermis. The Na⁺ /H⁺ exchanger NHE1 is one of the major contributors of acidity in superficial skin layers. It is also activated by the most frequent mutation in melanoma, BRAF^{V 600E} , thereby causing pH dysregulation during melanoma initiation. Melanoma progression is supported by an extracellular acidification and/or NHE1 activity which promote the escape of single melanoma cells from the primary tumour, migration and metastatic spreading. We propose that viewing melanoma against the background of the acid-base physiology of the skin provides a better understanding of the pathophysiology of this disease and allows the development of novel therapeutic concepts.

Rare Stochastic Expression of O6-Methylguanine- DNA Methyltransferase (MGMT) in MGMT-Negative Melanoma Cells Determines Immediate Emergence of Drug-Resistant Populations upon Treatment with Temozolomide In Vitro and In Vivo

The chemotherapeutic agent temozolomide (TMZ) kills tumor cells preferentially via alkylation of the O6-position of guanine. However, cells that express the DNA repair enzyme O6-methylguanine-DNA methyltransferase (MGMT), or harbor deficient DNA mismatch repair (MMR) function, are profoundly resistant to this drug. TMZ is in clinical use for melanoma, but objective response rates are low, even when TMZ is combined with O6-benzylguanine (O6BG), a potent MGMT inhibitor. We used in vitro and in vivo models of melanoma to characterize the early events leading to cellular TMZ resistance. Melanoma cell lines were exposed to a single treatment with TMZ, at physiologically relevant concentrations, in the absence or presence of O6BG. Surviving clones and mass cultures were analyzed by Western blot, colony formation assays, and DNA methylation studies. Mice with melanoma xenografts received TMZ treatment, and tumor tissue was analyzed by immunohistochemistry. We found that MGMT-negative melanoma cell cultures, before any drug treatment, already harbored a small fraction of MGMT-positive cells, which survived TMZ treatment and promptly became the dominant cell type within the surviving population. The MGMT-negative status in individual cells was not stable, as clonal selection of MGMT-negative cells again resulted in a mixed population harboring MGMT-positive, TMZ-resistant cells. Blocking the survival advantage of MGMT via the addition of O6BG still resulted in surviving clones, although at much lower frequency and independent of MGMT, and the resistance mechanism of these clones was based on a common lack of expression of MSH6, a key MMR enzyme. TMZ treatment of mice implanted with MGMT-negative melanoma cells resulted in effective tumor growth delay, but eventually tumor growth resumed, with tumor tissue having become MGMT positive. Altogether, these data reveal stochastic expression of MGMT as a pre-existing, key determinant of TMZ resistance in melanoma cell lines. Although MGMT activity can effectively be eliminated by pharmacologic intervention with O6BG, additional layers of TMZ resistance, although considerably rarer, are present as well and minimize the cytotoxic impact of TMZ/O6BG combination treatment. Our results provide rational explanations regarding clinical observations, where the TMZ/O6BG regimen has yielded mostly disappointing outcomes in melanoma patients.

Spindle cell melanoma: Incidence and survival, 1973-2017

Spindle cell melanoma (SCM) is a rare morphological subtype of melanoma, which is relatively uncharacterized. The aim of the present study was to investigate the incidence of SCM, its general demographics, basic clinico-pathologic features, treatment outcomes and disease-specific prognostic factors. SCM cases were sampled from the Surveillance, Epidemiology and End Results (SEER) Program (1973–2017). A total of 4761 SCM cases were identified, with a median age of 66 years. The female:male ratio was 0.62:1. Statistically significant overall survival (OS) and disease-specific survival (DSS) rate differences were identified depending on age, sex, ethnicity, tumor location, T stage, N stage, M stage, pathological grade, AJCC stage, SEER stages and surgical treatment (P<0.05). Multivariate Cox regression analysis revealed that age >66 years, T3+T4 stage disease, positive N stage and SEER historic stage of regional and distant metastasis tumor were associated with poor DSS and OS rates. In summary, SCM was most common in Caucasian people of 60~80 years of age with a predominance in males. Patient's age, ethnicity, T stage, N stage, and SEER historic stage were identified as independent prognostic factors of SCM in terms of DSS and OS.

Copper Silicate Hollow Microspheres-Incorporated Scaffolds for Chemo-Photothermal Therapy of Melanoma and Tissue Healing

The treatment of melanoma requires complete removal of tumor cells and simultaneous tissue regeneration of tumor-initiated cutaneous defects. Herein, copper silicate hollow microspheres (CSO HMSs)-incorporated bioactive scaffolds were designed for chemo-photothermal therapy of skin cancers and regeneration of skin tissue. CSO HMSs were synthesized with interior hollow and external nanoneedle microstructure, showing excellent drug-loading capacity and photothermal effects. With incorporation of drug-loaded CSO HMSs into the electrospun scaffolds, the composite scaffolds exhibited excellent photothermal effects and controlled NIR-triggered drug release, leading to distinctly synergistic chemo-photothermal therapy of skin cancer both in vitro and in vivo. Furthermore, such CSO HMSs-incorporated scaffolds could promote proliferation and attachment of normal skin cells and accelerate skin tissue healing in tumor-bearing and diabetic mice. Taken together, CSO HMSs-incorporated scaffolds may be used for complete eradication of the remaining tumor cells after surgery and simultaneous tissue healing, which offers an effective strategy for therapy and regeneration of tumor-initiated tissue defects.

Role of ubenimex as an anticancer drug and its synergistic effect with Akt inhibitor in human A375 and A2058 cells

Background

Malignant melanoma (MM) is a malignant tumor produced by changes in melanocytes in the skin or other organs. In the classification of skin tumor mortality, skin melanoma ranks the highest. Ubenimex, an Aminopeptidase N (APN) inhibitor, is now widely used for cancer as an adjunct therapy, conferring antitumor effects. Apoptosis and the induction of autophagy have both been found to be closely associated with tumor cell death.

Methods

In this study, the A375 and A2058 cell lines were treated with ubenimex. Cell viability was measured using the Cell Counting Kit 8 assay. Apoptosis and autophagic cell death were assessed using flow cytometry and acridine orange/ethidium bromide staining. Protein expression was assessed by Western blot analyses and immunofluorescence. Matrigel invasion and migration assays were used to examine the metastatic ability of melanoma cells.

Results

The results revealed that ubenimex inhibited the expression of APN in melanoma cells, which may be connected with the inhibition of metastasis. In addition, it increased melanoma cell death by inducing apoptosis and autophagic cell death. This effect was accompanied by increased levels of p-JNK. Moreover, treatment with ubenimex induced protective Akt activation, and combined use of an Akt inhibitor with ubenimex provided a better effect for inducing tumor cell death.

Conclusion

As an effective anti-tumor drug in vitro, ubenimex might be an excellent adjunctive therapy for the treatment of melanoma, with greater effects when combined with the use of an Akt inhibitor.

Innovative Therapy, Monoclonal Antibodies and Beyond

The seventh Edition of "Innovative Therapy, Monoclonal Antibodies and Beyond" Meeting took place in Milan, Italy, on January 27, 2017. The two sessions of the meeting were focused on: 1) Preclinical assays and novel biotargets; and 2) monoclonal antibodies, cell therapies and targeted molecules. Between these two sessions, a lecture entitled "HLA-antigens modulation and response to immune checkpoint inhibitor immunotherapy" was also presented. Despite the impressive successes in cancer immunotherapy in recent years, the response to immune based interventions occurs only in a minority of patients (∼20%). Several basic and translational mechanisms of resistance to immune checkpoint blockers (ICBs) were discussed during the meeting: 1. the impact of tumor microenvironment on the activity of immune system; 2. strategies to inhibit the cross-talk between extracellular matrix and myeloid-derived suppressor cells (MDSC) in the preclinical setting; 3. microRNA expression as a biomarker and as a target of therapy in non-small cell lung cancer (NSCLC); 4. the significance of complement activation pathways in response to immune checkpoint inhibitors; 5. the immunosuppressive activity of the microbiota by inducing IL-17 producing cells; and 6. modulation of HLA antigens as possible markers of response to ICB therapy. In order to overcome the deficiency in active anti-tumor T cells, several clinically applicable combination strategies were also discussed: 1. strategies to enhance the anticancer effects of immunogenic cell death inducing-chemotherapy; 2. the use of CAR T-cells in solid tumors; 3. the use of combination strategies involving oncolytic viruses and ICBs; 4. combinations of new ICBs with anti-PD-1/CTLA-4 therapy; and 4. combinations of targeted therapies and ICBs in melanoma. Overall, this conference emphasized the many novel strategies that are being investigated to improve the overall patient response to cancer immunotherapy. Optimization of biomarkers to accurately select patients who will respond to immunotherapy, coupled with combination strategies to improve long term patient survival remain critical challenges in the immuno-oncology field.