Combinatorial Effect of Cold Atmosphere Plasma (CAP) and the Anticancer Drug Cisplatin on Oral Squamous Cell Cancer Therapy

Synergistic effect of cold gas plasma and experimental drug exposure exhibits skin cancer toxicity in vitro and in vivo

INTRODUCTION

Skin cancer is often fatal, which motivates new therapy avenues. Recent advances in cancer treatment are indicative of the importance of combination treatments in oncology. Previous studies have identified small molecule-based therapies and redox-based technologies, including photodynamic therapy or medical gas plasma, as promising candidates to target skin cancer.

OBJECTIVE

We aimed to identify effective combinations of experimental small molecules with cold gas plasma for therapy in dermato-oncology.

METHODS

Promising drug candidates were identified after screening an in-house 155-compound library using 3D skin cancer spheroids and high content imaging. Combination effects of selected drugs and cold gas plasma were investigated with respect to oxidative stress, invasion, and viability. Drugs that had combined well with cold gas plasma were further investigated in vascularized tumor organoids in ovo and a xenograft mouse melanoma model in vivo.

RESULTS

The two chromone derivatives Sm837 and IS112 enhanced cold gas plasma-induced oxidative stress, including histone 2A.X phosphorylation, and further reduced proliferation and skin cancer cell viability. Combination treatments of tumor organoids grown in ovo confirmed the principal anti-cancer effect of the selected drugs. While one of the two compounds exerted severe toxicity in vivo, the other (Sm837) resulted in a significant synergistic anti-tumor toxicity at good tolerability. Principal component analysis of protein phosphorylation profiles confirmed profound combination treatment effects in contrast to the monotherapies.

CONCLUSION

We identified a novel compound that, combined with topical cold gas plasma-induced oxidative stress, represents a novel and promising treatment approach to target skin cancer.

Drug release control and anti-inflammatory effect of biodegradable polymer surface modified by gas phase chemical functional reaction

The plasma technique has been widely used to modify the surfaces of materials. The purpose of this study was to evaluate the probability of controlling the prednisolone delivery velocity on a polylactic acid (PLA) surface modified by plasma surface treatment. Surface modification of PLA was performed at a low-pressure radio frequency under conditions of 100 W power, 50 mTorr chamber pressure, 100-200 sccm of flow rate, and Ar, O2, and CH4gases. The plasma surface-modified PLA was characterized using scanning emission microscope, x-ray photoelectron spectroscopy (XPS), and contact angle measurements.In vitroevaluations were performed to determine cellular response, drug release behavior, and anti-inflammatory effects. The PLA surface morphology was changed to a porous structure (with a depth of approximately 100 μm) and the surface roughness was also significantly increased. The XPS results demonstrated higher oxygenized carbon contents than those in the non-treated PLA group. The prednisolone holding capacity increased and the release was relatively prolonged in the surface-modified PLA group compared to that in the non-treated PLA group. In addition, cell migration and proliferation significantly increased after PLA treatment alone. The activity of cytokines such as cyclooxygenase-2 (COX-2), tumor necrosis factor-a (TNF-α), interleukin (IL-1β), and IL-6 were considerably reduced in the plasma-treated and prednisolone holding group. Taken together, surface-modified PLA by plasma can provide an alternative approach to conventional physicochemical approaches for sustained anti-inflammatory drug release.

Cold atmospheric plasma stabilizes mismatch repair for effective, uniform treatment of diverse colorectal cancer cell types

Mismatch Repair (MMR) mechanisms play a pivotal role in rectifying DNA replication errors and maintaining the stability of DNA microsatellite structure. Colorectal cancer (CRC) can be characterized into microsatellite stability (MSS) and microsatellite instability (MSI) subtypes based on the functionality of MMR. MSI CRC notably exhibits enhanced chemotherapy resistance, attributable to diminished MMR-related protein expression. Cold atmospheric plasma (CAP) has emerged as a promising treatment modality, demonstrating efficacy in inducing apoptosis in various cancer cells. However, the therapeutic impact of CAP on MSI colorectal cancer, and the underlying mechanisms remain elusive. In this study, we investigated the effects of CAP on MSI (MC38, HCT116, and LOVO) and MSS (CT26 and HT29) CRC cell lines. We are probing into the products of CAP treatment. Our findings indicate that CAP treatment induces comparable effects on apoptosis, reactive oxygen species (ROS), and reactive nitrogen species (RNS), as well as the expression of apoptosis-related proteins in both MSI and MSS cells. Mechanistically, CAP treatment led to an elevation in the expression of mismatch repair proteins (MLH1 and MSH2), particularly in MSI cells, which notably have been proven to facilitate the activation of apoptosis-related proteins. Collectively, our study reveals that CAP enhances apoptotic signaling and induces apoptosis in MSI colorectal cancer cells by upregulating the expression of MMR-related proteins, thereby reinforcing MMR stabilization.

Cold atmospheric plasma sensitizes head and neck cancer to chemotherapy and immune checkpoint blockade therapy

Head and neck cancer (HNC) is the seventh most prevalent cancer globally, often characterized by chemo-resistance and immunosuppression, which significantly hampers treatment efficacy. Cold atmospheric plasma (CAP) has recently emerged as a promising adjuvant oncotherapy with substantial potential and advantages. In this study, Piezobrush® PZ2, a handheld CAP unit based on the piezoelectric direct discharge technology, was used to generate and deliver non-thermal plasma. We aimed to investigate the effects of CAPPZ2 on various types of HNC cells and elucidate the underlying mechanisms. In addition, we endeavored to examine the efficacy of combining CAPPZ2 with chemotherapy drugs (i.e., cisplatin) or immune checkpoint blockade (ICB, i.e., PD1 antibody) in HNC treatment. Firstly, the results demonstrated that CAPPZ2 exerted anti-neoplastic functions through inhibiting cell proliferation, migration and invasion, and promoting apoptosis and autophagy. Secondly, using transcriptomic sequencing, Western blotting, and quantitative real-time PCR, the mechanisms underlying CAPPZ2 treatment in vitro was presumed to be a multitargeted blockade of major cancer survival pathways, such as redox balance, glycolysis, and PI3K/AKT/mTOR/HIF-1α signaling. Lastly, combinatorial thearpy containing CAPPZ2 and cisplatin or PD-1 antibody significantly suppressed tumor growth and prolonged recipient survival in vivo. Collectively, the synergistic effects of CAPPZ2 and cisplatin or PD-1 antibody could serve as a promising solution to enhance head and neck tumor elimination.

New insights into redox-related risk factors and therapeutic targets in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is the most common cancer in the oral cavity accounting for 90 % of oral cancer with a global incidence of 350.000 new cases per year. Curative resection along with adjuvant radiation therapy or a combination of radiotherapy with chemotherapy remain as gold standard in treating OSCC. Still, local recurrence, lymph nodal recurrence, and complications of radiation remain the main cause of tumor-related mortality. Reactive oxygen species are not only correlated to the etiology of OSCC due to oxidative DNA damage, lipid peroxidation or effecting signal transduction cascades that effect cell proliferation and tumorigenesis, but are also of great interest in the therapy of OSCC patients. As induced oxidative stress can be used therapeutically for the induction of tumor cell death, redox targets might be a therapeutic addition to the conventional treatment options. In this review, we discuss markers of impaired redox homeostasis as well as potential redox-related treatment targets in OSCC.

Cold Atmospheric Plasma Jet Irradiation Decreases the Survival and the Expression of Oncogenic miRNAs of Oral Carcinoma Cells

Despite recent advancements, therapies against advanced oral squamous cell carcinoma (OSCC) remain ineffective, resulting in unsatisfactory therapeutic outcomes. Cold atmospheric plasma (CAP) offers a promising approach in the treatment of malignant neoplasms. Although the effects of CAP in abrogating OSCC have been explored, the exact mechanisms driving CAP-induced cancer cell death and the changes in microRNA (miRNA) expression are not fully understood. We fabricated and calibrated an argon-CAP device to explore the effects of CAP irradiation on the growth and expression of oncogenic miRNAs in OSCC. The analysis revealed that, in OSCC cell lines following CAP irradiation, there was a significant reduction in viability; a downregulation of miR-21, miR-31, miR-134, miR-146a, and miR-211 expression; and an inactivation of the v-akt murine thymoma viral oncogene homolog (AKT) and extracellular signal-regulated kinase (ERK) signals. Pretreatment with blockers of apoptosis, autophagy, and ferroptosis synergistically reduced CAP-induced cell death, indicating a combined induction of variable death pathways via CAP. Combined treatments using death inhibitors and miRNA mimics, alongside the activation of AKT and ERK following the exogenous expression, counteracted the cell mortality associated with CAP. The CAP-induced downregulation of miR-21, miR-31, miR-187, and miR-211 expression was rescued through survival signaling. Additionally, CAP irradiation notably inhibited the growth of SAS OSCC cell xenografts on nude mice. The reduced expression of oncogenic miRNAs in vivo aligned with in vitro findings. In conclusion, our study provides new lines of evidence demonstrating that CAP irradiation diminishes OSCC cell viability by abrogating survival signals and oncogenic miRNA expression.

Beyond traditional therapy: Mucoadhesive polymers as a new frontier in oral cancer management

In recent times mucoadhesive drug delivery systems are gaining popularity in oral cancer. It is a malignancy with high global prevalence. Despite significant advances in cancer therapeutics, improving the prognosis of late-stage oral cancer remains challenging. Targeted therapy using mucoadhesive polymers can improve oral cancer patients' overall outcome by offering enhanced oral mucosa bioavailability, better drug distribution and tissue targeting, and minimizing systemic side effects. Mucoadhesive polymers can also be delivered via different formulations such as tablets, films, patches, gels, and nanoparticles. These polymers can deliver an array of medicines, making them an adaptable drug delivery approach. Drug delivery techniques based on these mucoadhesive polymers are gaining traction and have immense potential as a prospective treatment for late-stage oral cancer. This review examines leading research in mucoadhesive polymers and discusses their potential applications in treating oral cancer.

Exploring the Use of Cold Atmospheric Plasma to Overcome Drug Resistance in Cancer

Drug resistance is a major problem in cancer treatment, as it limits the effectiveness of pharmacological agents and can lead to disease progression. Cold atmospheric plasma (CAP) is a technology that uses ionized gas (plasma) to generate reactive oxygen and nitrogen species (RONS) that can kill cancer cells. CAP is a novel approach for overcoming drug resistance in cancer. In recent years, there has been a growing interest in using CAP to enhance the effectiveness of chemotherapy drugs. In this review, we discuss the mechanisms behind this phenomenon and explore its potential applications in cancer treatment. Going through the existing literature on CAP and drug resistance in cancer, we highlight the challenges and opportunities for further research in this field. Our review suggests that CAP could be a promising option for overcoming drug resistance in cancer and warrants further investigation.

Plasma oncology: Adjuvant therapy for head and neck cancer using cold atmospheric plasma

The worldwide incidence of head and neck cancer (HNC) exceeds half a million cases annually, and up to half of the patients with HNC present with advanced disease. Surgical resection remains the mainstay of treatment for many HNCs, although radiation therapy, chemotherapy, targeted therapy, and immunotherapy might contribute to individual patient’s treatment plan. Irrespective of which modality is chosen, disease prognosis remains suboptimal, especially for higher staging tumors. Cold atmospheric plasma (CAP) has recently demonstrated a substantial anti-tumor effect. After a thorough literature search, we provide a comprehensive review depicting the oncological potential of CAP in HNC treatment. We discovered that CAP applies to almost all categories of HNC, including upper aerodigestive tract cancers, head and neck glandular cancers and skin cancers. In addition, CAP is truly versatile, as it can be applied not only directly for superficial or luminal tumors but also indirectly for deep solid organ tumors. Most importantly, CAP can work collaboratively with existing clinical oncotherapies with synergistic effect. After our attempts to elaborate the conceivable molecular mechanism of CAP’s anti-neoplastic effect for HNC, we provide a brief synopsis of recent clinical and preclinical trials emphasizing CAP’s applicability in head and neck oncology. In conclusion, we have enunciated our vision of plasma oncology using CAP for near future HNC treatment.

Antiproliferative and Apoptotic Effects of Graphene Oxide @AlFu MOF Based Saponin Natural Product on OSCC Line

The increasing rate of oral squamous cell carcinoma (OSCC) and the undesirable side effects of anticancer agents have enhanced the demand for the development of efficient, detectable, and targeted anticancer systems. Saponins are a diverse family of natural glycosides that have recently been evaluated as an effective compound for the targeted therapy of squamous cell carcinoma. Due to their porous nature and stable structure, metal–organic frameworks (MOFs) are a well-known substance form for various biological applications, such as drug delivery. In this study, we fabricated a novel hybrid, highly porous and low-toxic saponin-loaded nanostructure by modifying graphene oxide (GO)/reduced GO (rGO) with aluminum fumarate (AlFu) as MOF core–shell nanocomposite. The characterization of the nanostructures was investigated by FTIR, TEM, EDX, FESEM, and BET. MTT assay was used to investigate the anticancer activity of these compounds on OSCC and PDL normal dental cells. The effect of the nanocomposites on OSCC was then investigated by studying apoptosis and necrosis using flow cytometry. The GO/rGO was decorated with a saponin–AlFu mixture to further investigate cytotoxicity. The results of the MTT assay showed that PDL cells treated with AlFu–GO–saponin at a concentration of 250 μg/mL had a viability of 74.46 ± 16.02%, while OSCC cells treated with this sample at a similar concentration had a viability of only 38.35 ± 19.9%. The anticancer effect of this nanostructure on OSCC was clearly demonstrated. Moreover, the number of apoptotic cells in the AlFu–GO–saponin and AlFu–rGO–saponin groups was 10.98 ± 2.36%–26.90 ± 3.24% and 15.9 ± 4.08%–29.88 ± 0.41%, respectively, compared with 2.52 ± 0.78%–1.31 ± 0.62% in the untreated group. This significant increase in apoptotic effect observed with AlFu–rGO–saponin was also reflected in the significant anticancer effect of saponin-loaded nanostructures. Therefore, this study suggests that an effective saponin delivery system protocol for the precise design and fabrication of anticancer nanostructures for OSCC therapy should be performed prior to in vivo evaluations.

Open Questions in Cold Atmospheric Plasma Treatment in Head and Neck Cancer: A Systematic Review

Over the past decade, we witnessed a promising application of cold atmospheric plasma (CAP) in cancer therapy. The aim of this systematic review was to provide an exhaustive state of the art of CAP employed for the treatment of head and neck cancer (HNC), a tumor whose late diagnosis, local recurrence, distant metastases, and treatment failure are the main causes of patients’ death. Specifically, the characteristics and settings of the CAP devices and the in vitro and in vivo treatment protocols were summarized to meet the urgent need for standardization. Its molecular mechanisms of action, as well as the successes and pitfalls of current CAP applications in HNC, were discussed. Finally, the interesting emerging preclinical hypotheses that warrant further clinical investigation have risen. A total of 24 studies were included. Most studies used a plasma jet device (54.2%). Argon resulted as the mostly employed working gas (33.32%). Direct and indirect plasma application was reported in 87.5% and 20.8% of studies, respectively. In vitro investigations were 79.17%, most of them concerned with direct treatment (78.94%). Only eight (33.32%) in vivo studies were found; three were conducted in mice, and five on human beings. CAP showed pro-apoptotic effects more efficiently in tumor cells than in normal cells by altering redox balance in a way that oxidative distress leads to cell death. In preclinical studies, it exhibited efficacy and tolerability. Results from this systematic review pointed out the current limitations of translational application of CAP in the urge of standardization of the current protocols while highlighting promising effects as supporting treatment in HNC.

Cold Atmospheric Plasma Targeting Hematological Malignancies: Potentials and Problems of Clinical Translation

Cold atmospheric plasma is an ionized gas produced near room temperature; it generates reactive oxygen species and nitrogen species and induces physical changes, including ultraviolet, radiation, thermal, and electromagnetic effects. Several studies showed that cold atmospheric plasma could effectively provoke death in a huge amount of cell types, including neoplastic cells, via the induction of apoptosis, necrosis, and autophagy. This technique seems able to destroy tumor cells by disturbing their more susceptible redox equilibrium with respect to normal cells, but it is also able to cause immunogenic cell death by enhancing the immune response, to decrease angiogenesis, and to provoke genetic and epigenetics mutations. Solutions activated by cold gas plasma represent a new modality for treatment of less easily reached tumors, or hematological malignancies. Our review reports on accepted knowledge of cold atmospheric plasma’s effect on hematological malignancies, such as acute and chronic myeloid leukemia and multiple myeloma. Although relevant progress was made toward understanding the underlying mechanisms concerning the efficacy of cold atmospheric plasma in hematological tumors, there is a need to determine both guidelines and safety limits that guarantee an absence of long-term side effects.

Gas plasma-oxidized sodium chloride acts via hydrogen peroxide in a model of peritoneal carcinomatosis

Gas plasma technology generates reactive oxygen and nitrogen species (ROS/RNS), inducing lethal oxidative damage in tumor cells. The transfer of gas plasma-derived ROS/RNS into liquids has been proposed as an innovative anti-cancer strategy targeting peritoneal carcinomatosis (PC). However, the mechanism of action is under debate. To this end, we compared gas plasma-oxidized medical-grade sodium chloride (oxNaCl) with a concentration-matched control (cmc) of NaCl enriched with equivalent concentrations of H₂O₂ and NO₃^- in several cell lines and models of PC. Strikingly, oxNaCl and cmc performed equally well in oxidation and cytotoxic activity in tumor cells in two-dimensional cultures, three-dimensional (3D) tumor spheroids, vascularized 3D tumors grown on chicken-embryo chorioallantoic membranes, and a syngeneic PC mouse model in vivo. Given the importance of immunotherapies in oncology today, we focused on immunological consequences of the treatment. Again, to a similar extent, oxNaCl and cmc increased tumor cell immunogenicity and enhanced uptake by and maturation of peripheral blood monocyte-derived dendritic cells together with an inflammatory secretion profile. Furthermore, NanoString gene expression profiling revealed immune system processes and unfolded protein response-related pathways as being linked to the observed anti-tumor effects for both oxNaCl and cmc. In conclusion, gas plasma-generated oxNaCl and cmc showed equal therapeutic efficacy in our PC-related models. In light of the many promising anti-cancer studies of gas plasma-oxidized liquids and the convenient production of corresponding cmcs in large quantities as needed in clinics, our findings may spur research lines based on low-dose oxidants in peritoneal cancer therapy.

Plasma Dermatology: Skin Therapy Using Cold Atmospheric Plasma

Cold atmospheric plasma-based plasma medicine has been expanding the diversity of its specialties. As an emerging branch, plasma dermatology takes advantage of the beneficial complexity of plasma constituents (e.g., reactive oxygen and nitrogen species, UV photons, and electromagnetic emission), technical versatility (e.g., direct irradiation and indirect aqueous treatment), and practical feasibility (e.g., hand-held compact device and clinician-friendly operation). The objective of this comprehensive review is to summarize recent advances in the CAP-dominated skin therapy by broadly covering three aspects. We start with plasma optimisation of intact skin, detailing the effect of CAP on skin lipids, cells, histology, and blood circulation. We then conduct a clinically oriented and thorough dissection of CAP treatment of various skin diseases, focusing on the wound healing, inflammatory disorders, infectious conditions, parasitic infestations, cutaneous malignancies, and alopecia. Finally, we conclude with a brief analysis on the safety aspect of CAP treatment and a proposal on how to mitigate the potential risks. This comprehensive review endeavors to serve as a mini textbook for clinical dermatologists and a practical manual for plasma biotechnologists. Our collective goal is to consolidate plasma dermatology’s lead in modern personalized medicine.

Primary cold atmospheric plasma combined with low dose cisplatin as a possible adjuvant combination therapy for HNSCC cells-an in-vitro study

BACKGROUND

The aim of the present study was to examine the cytostatic effects of cold atmospheric plasma (CAP) on different head and neck squamous carcinoma (HNSCC) cell lines either in isolation or in combination with low dose cisplatin. The effect of CAP treatment was investigated by using three different HNSCC cell lines (chemo-resistant Cal 27, chemo-sensitive FaDu and OSC 19).

MATERIALS AND METHOD

Cell lines were exposed to CAP treatment for 30, 60, 90, 120 and 180 s (s). Cisplatin was added concurrently (cc) or 24 h after CAP application (cs). Cell viability, DNA damage and apoptosis was evaluated by dye exclusion, MTT, alkaline microgel electrophoresis assay and Annexin V-Fit-C/PI respectively.

RESULTS

In all cell lines, 120 s of CAP exposure resulted in a significant reduction of cell viability. DNA damage significantly increased after 60 s. Combined treatment of cells with CAP and low dose cisplatin showed additive effects. A possible sensitivity to cisplatin could be restored in Cal 27 cells by CAP application.

CONCLUSION

CAP shows strong cytostatic effects in HNSCC cell lines that can be increased by concurrent cisplatin treatment, suggesting that CAP may enhance the therapeutic efficacy of low dose cisplatin.

Applications of Plasma-Activated Water in Dentistry: A Review

The activation of water by non-thermal plasma creates a liquid with active constituents referred to as plasma-activated water (PAW). Due to its active constituents, PAW may play an important role in different fields, such as agriculture, the food industry and healthcare. Plasma liquid technology has received attention in recent years due to its versatility and good potential, mainly focused on different health care purposes. This interest has extended to dentistry, since the use of a plasma–liquid technology could bring clinical advantages, compared to direct application of non-thermal atmospheric pressure plasmas (NTAPPs). The aim of this paper is to discuss the applicability of PAW in different areas of dentistry, according to the published literature about NTAPPs and plasma–liquid technology. The direct and indirect application of NTAPPs are presented in the introduction. Posteriorly, the main reactors for generating PAW and its active constituents with a role in biomedical applications are specified, followed by a section that discusses, in detail, the use of PAW as a tool for different oral diseases.

Effect of Cold Atmospheric Plasma on Epigenetic Changes, DNA Damage, and Possibilities for Its Use in Synergistic Cancer Therapy

Cold atmospheric plasma has great potential for use in modern medicine. It has been used in the clinical treatment of skin diseases and chronic wounds, and in laboratory settings it has shown effects on selective decrease in tumour-cell viability, reduced tumour mass in animal models and stem-cell proliferation. Many researchers are currently focusing on its application to internal structures and the use of plasma-activated liquids in tolerated and effective human treatment. There has also been analysis of plasma's beneficial synergy with standard pharmaceuticals to enhance their effect. Cold atmospheric plasma triggers various responses in tumour cells, and this can result in epigenetic changes in both DNA methylation levels and histone modification. The expression and activity of non-coding RNAs with their many important cell regulatory functions can also be altered by cold atmospheric plasma action. Finally, there is ongoing debate whether plasma-produced radicals can directly affect DNA damage in the nucleus or only initiate apoptosis or other forms of cell death. This article therefore summarises accepted knowledge of cold atmospheric plasma's influence on epigenetic changes, the expression and activity of non-coding RNAs, and DNA damage and its effect in synergistic treatment with routinely used pharmaceuticals.

WSG, a glucose-enriched polysaccharide from Ganoderma lucidum, suppresses tongue cancer cells via inhibition of EGFR-mediated signaling and potentiates cisplatin-induced apoptosis

Tongue cancer, a kind of oral cancer, is common in Southeast Asian countries because of dietary habits. However, there is no specific targeted drug that could effectively inhibit oral cancer. WSG, as a water soluble glucose-enriched polysaccharide from Ganoderma lucidum, exerts excellent pharmacological efficacy of anti-lung cancer. However, its anticancer functions and mechanisms in human tongue cancer need to be further explored. Herein, we showed that WSG dramatically reduced cell viability and colony formation of tongue cancer cells. WSG increased subG1 and G2/M populations as well as induced apoptotic responses. In parallel, WSG enhanced apoptosis-related Bax/Bcl2 ratio. Mechanistic studies showed that WSG reduced phosphorylation of EGFR and AKT. In addition, we found a synergistic effect of WSG with cisplatin in inhibition of cell viability and induction of apoptosis. WSG significantly reduced the inhibition concentration 50% (IC₅₀) of cisplatin. More importantly, WSG ameliorated cisplatin-induced cytotoxicity in normal human oral epithelial SG cells. In conclusion, our findings provided important insights into the anti-tongue cancer effects of WSG via inhibition of EGFR/AKT axis and induction of apoptosis, which indicated that WSG could be a promising supplement for tongue cancer treatment.

Synergistic effect of cold atmospheric pressure plasma and free or liposomal doxorubicin on melanoma cells

The aim of the present study was to investigate combined effects of cold atmospheric plasma (CAP) and the chemotherapeutic drug doxorubicin (DOX) on murine and human melanoma cells, and normal cells. In addition to free drug, the combination of CAP with a liposomal drug (DOX-LIP) was also studied for the first time. Thiazolyl blue tetrazolium bromide (MTT) and Trypan Blue exclusion assays were used to evaluate cell viability; the mechanism of cell death was evaluated by flow cytometry. Combined treatment effects on the clonogenic capability of melanoma cells, was also tested with soft agar colony formation assay. Furthermore the effect of CAP on the cellular uptake of DOX or DOX-LIP was examined. Results showed a strong synergistic effect of CAP and DOX or DOX-LIP on selectively decreasing cell viability of melanoma cells. CAP accelerated the apoptotic effect of DOX (or DOX-LIP) and dramatically reduced the aggressiveness of melanoma cells, as the combination treatment significantly decreased their anchorage independent growth. Moreover, CAP did not result in increased cellular uptake of DOX under the present experimental conditions. In conclusion, CAP facilitates DOX cytotoxic effects on melanoma cells, and affects their metastatic potential by reducing their clonogenicity, as shown for the first time.