melitten and Carcinoma--Squamous-Cell

Cervical cancer has recently become one of the most prevalent cancers among women throughout the world. Traditional cancer therapies generate side effects due to off-target toxicity. Thus, novel cancer medications coupled with suitable drug delivery systems are required to improve cancer therapies. Melittin peptide has a high affinity to disrupt cancer cells. In this study, we designed targeted and redox-responsive Melittin conjugates for cervical cancer and then tested them in vitro. Folic acid and squamous cell carcinoma-specific peptide (CKQNLAEG) were used as targeting agents to design various conjugates. Our findings indicate that both anticancer conjugates were effective against different cancer cell lines, including MCF-7, C33A, and HeLa. Moreover, these conjugates were found to have antioxidant and antibacterial effects as well as reduced hemolytic activity. The CM-Target (N-terminus cysteine modified-Melittin-targeting peptide-functionalized conjugate) has become more stable and acted specifically against squamous cell carcinoma, whereas folic acid (FA)-containing conjugates acted efficiently against all cancer types studied, especially for breast cancer. According to our results, these anticancer conjugates may be possible anticancer drug candidates that have fewer adverse effects.

Topics: Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Line, Tumor; Female; Folic Acid; HeLa Cells; Humans; Melitten; Oxidation-Reduction; Pharmaceutical Preparations; Uterine Cervical Neoplasms

Combined 5-fluorouracil (5-FU) and melittin (MEL) is believed to enhance cytotoxic effects on skin squamous cell carcinoma (SCC). However, the rationale underlying cytotoxicity is fundamentally important for a proper design of combination chemotherapy, and to provide translational insights for future therapeutics in the dermatology field. The aim was to elucidate the effects of 5-FU/MEL combination on the viability, proliferation and key structures of human squamous cell carcinoma (A431). Morphology, plasma membrane, DNA, mitochondria, oxidative stress, cell viability, proliferation and cell death pathways were targeted for investigation by microscopy, MTT, trypan blue assay, flow cytometry and real-time cell analysis. 5-FU/MEL (0.25 µM/0.52 µM) enhanced the cytotoxic effect in A431 cells (74.46%, p < .001) after 72 h exposure, showing greater cytotoxic effect when compared to each isolated compound (45.55% 5-FU and 61.78% MEL). The results suggest that MEL induces plasma membrane alterations that culminate in a loss of integrity at subsequent times, sensitizing the cell to 5-FU action. DNA fragmentation, S and G2/M arrest, disruption of mitochondrial metabolism, and alterations in cell morphology culminated in proliferation blockage and apoptosis. 5-FU/MEL combination design optimizes the cytotoxic effects of each drug at lower concentrations, which may represent an innovative strategy for SCC therapy.

Topics: Antimetabolites, Antineoplastic; Apoptosis; Carcinoma, Squamous Cell; Fluorouracil; G2 Phase Cell Cycle Checkpoints; Humans; Melitten; Signal Transduction; Skin Neoplasms; Treatment Outcome; Up-Regulation

Cationic antimicrobial peptides are ancient natural broad-spectrum antibiotics, and several compounds also exhibit anticancer activity. However, most applications pertain to bacterial infections, and treatment for skin cancer is less frequently considered. The cytotoxicity of melittin, cecropin A, protegrin-1 and histatin 5 against squamous skin cancer cell lines and normal human keratinocytes was evaluated and compared to established drugs. The results show that melittin clearly outperforms 5-fluorouracil regarding antitumor activity. Importantly, combined melittin and 5-fluorouracil enhanced cytotoxic effects on cancer cells and reduced toxicity on normal keratinocytes. Additionally, minimum inhibitory concentrations indicate that melittin also shows superior activity against clinical and laboratory strains of Candida albicans compared to amphotericin B. To evaluate its potential for topical applications, human skin penetration of melittin was investigated ex vivo and compared to two non-toxic cell-penetrating peptides (CPPs), low molecular weight protamine (LMWP) and penetratin. The stratum corneum prevents penetration into viable epidermis over 6 h; however, the peptides gain access to the viable skin after 24 h. Inhibition of digestive enzymes during skin penetration significantly enhances the availability of intact peptide. In conclusion, melittin may represent an innovative agent for non-melanoma skin cancer and infectious skin diseases. In order to develop a drug candidate, skin absorption and proteolytic digestion by skin enzymes need to be addressed.

Topics: Amphotericin B; Antifungal Agents; Antimicrobial Cationic Peptides; Antineoplastic Agents; Candida albicans; Carcinoma, Squamous Cell; Carrier Proteins; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cell-Penetrating Peptides; Enzyme-Linked Immunosorbent Assay; Fluorouracil; Humans; Keratinocytes; Melitten; Peptides; Protamines; Skin; Skin Neoplasms

Currently, unresectable esophageal squamous cell carcinoma (ESCC) is primarily treated by chemoradiotherapy. However, the outcome has not improved significantly because of radioresistance of cancer cells. This study aimed to determine the radiosensitizing effect of melittin, a novel component of bee venom, in ESCC. ESCC cell lines were irradiated with or without melittin. Cell proliferation was detected by Cell Counting Kit 8 assay. Radiosensitization was evaluated by clonogenic survival assay. Cell apoptosis was detected by flow cytometry. Results show that melittin potently sensitized ESCC cells to radiation with a sensitization enhancement ratio of 1.15-1.42. Radiosensitization was accompanied with enhanced apoptosis and regulated by apoptosis proteins. The results were confirmed by in vivo studies on tumor-bearing xenografts. In summary, these results provide support that melittin may be a potentially promising radiosensitizer in ESCC radiation therapy.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Cell Survival; Chemoradiotherapy; Dose-Response Relationship, Drug; Dose-Response Relationship, Radiation; Esophageal Neoplasms; Flow Cytometry; Humans; Immunoblotting; Male; Melitten; Mice, Inbred BALB C; Mice, Nude; Microscopy, Confocal; Proto-Oncogene Proteins c-bcl-2; Radiation-Sensitizing Agents; Xenograft Model Antitumor Assays

Hypoxia is a widespread phenomenon present in many human solid tumors and is associated with a poor prognosis and therapy resistance. Here, we tested the feasibility of melittin, a major component of bee venom, on radiosensitization of hypoxic head and neck squamous cell carcinoma (HNSCC). CNE-2 and KB cells were treated with melittin and radiation response was determined. Cell viability, cytotoxicity and apoptosis induction were examined by CCK-8 assay, colony formation assay, and flow cytometry. Expression of hypoxia-inducible factor 1-alpha (HIF-1α) and vascular endothelial growth factor (VEGF) proteins were assessed using western blotting. Additionally, we also examined the effect of melittin on tumor growth and radiosensitivity in vivo using a xenograft model of HNSCC. Treatment with melittin resulted in cell growth inhibition, induction of cell apoptosis, and reduction of HIF-1α and VEGF expression, which has been linked to hypoxia cell radioresistance. In addition, intraperitoneal injection of melittin significantly reduced the growth of HNSCC tumors in CNE-2 tumor-bearing mice. These data suggest that melittin enhances radiosensitivity of HNSCC under hypoxia condition, and this is associated with the suppression of HIF-1α expression. Melittin appears to be a potential radiotherapy sensitization agent due to its significant antihypoxia activity.

Topics: Animals; Apoptosis; Blotting, Western; Carcinoma, Squamous Cell; Cell Hypoxia; Head and Neck Neoplasms; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Male; Melitten; Mice; Mice, Inbred BALB C; Radiation-Sensitizing Agents; Squamous Cell Carcinoma of Head and Neck; Xenograft Model Antitumor Assays

Topics: Animals; Antineoplastic Agents; Bee Venoms; Carcinoma, Squamous Cell; Drug Carriers; Humans; Melanoma; Melitten; Mice; Nanospheres; Neoplasms; Precancerous Conditions; Skin Neoplasms; Xenograft Model Antitumor Assays