Mcl-1 Inhibitor Induces Cells Death in BRAF-Mutant Amelanotic Melanoma Trough GSH Depletion, DNA Damage and Cell Cycle Changes

Abstract

Mcl-1 is a potent antiapoptotic protein and amplifies frequently in many human cancer. Currently, it is considered that the extensively expressed of Mcl-1 protein in melanoma cells is associated with rapid tumor progression, poor prognosis and low chemosensitivity. Therefore, the antiapoptotic protein Mcl-1 could be considered as a potential target for malignant melanoma treatment. The aim of this study was to assess the effect of MIM1 a specific low molecular Mcl-1 protein inhibitor and mixture of MIM1 and dacarbazine on the viability, cell cycle progression and apoptosis induction in amelanotic C32 melanoma cells. The cytotoxic activity of MIM1 towards C32 melanoma cells was examined by the WST-1 test. The Mcl-1 protein level as a drug target in amelanotic melanoma cells was defined by Western blot analysis. Cell cycle progression, DNA fragmentation as well as GSH depletion were determined by fluorescence image cytometer NucleoCounter NC-3000. The obtained results demonstrate that the specific Mcl-1 protein inhibitor-MIM1 decreases cell viability and induce apoptosis (S-phase arrest, DNA fragmentation and redox imbalance) in amelanotic melanoma cells and intensify the proapoptotic properties of DTIC, as a result of interactions with Mcl-1 protein. Taken together, the presented data suggest that Mcl-1 protein is a an important target in malignant melanoma treatment and provide for the first time convincing evidence that MIM1, which inhibits Mcl-1 antiapoptotic protein is able to induce apoptosis and sensitize melanoma cells to alkylating agent.

The Anticancer Potential of Doxycycline and Minocycline—A Comparative Study on Amelanotic Melanoma Cell Lines

“…The observations indicate that dacarbazine, even after 72 h, mainly inhibits cell proliferation but does not induce melanoma cell death. The effect was confirmed by cell cycle analysis and was related to a slight increase in the cell percentage in the G1/G0 phase [ 58 ]. In the case of A375 cells, dacarbazine at the near-therapeutic concentration of 40 µM reduced cell viability by less than 15% after 48 h of incubation.…”

“…In turn, the treatment with dacarbazine at 50 µM for 72 h decreased the viability of melanotic melanoma COLO829 only to 75% [ 57 ]. Although analogous conditions for the C32 cell line caused a 55% decrease, the number of dead cells increased by only 6% [ 58 ]. In turn, 48 h of treatment of C32 cells with 200 µM and 400 µM of doxycycline caused an increase in the percentage of dead cells to 43.3% and 61.0%, respectively.…”

“…The obtained EC 50 values for moxifloxacin were 150 µM and 110 µM, respectively [ 64 ]. In turn, MIM1 decreased cell viability by around 50% in a concentration of 50 µM [ 57 , 58 ].…”

Targeting MCL-1 in cancer: current status and perspectives

“…Combined inhibition of MCL-1 and BCL-xL by S63845/S64315 plus Navitoclax [ 149 ] or the combination of MCL-1 and BCL-2 by S63845/S64315 plus ABT-199 [ 150 ] synergistically induces extensive death in advanced/refractory melanoma cell lines both in vitro and in vivo. MIM1 promotes mitochondrial membrane rupture, glutathione depletion and cell cycle arrest, inducing melanoma cell death [ 151 , 152 ].…”

Ketoprofen Combined with UVA Irradiation Exerts Higher Selectivity in the Mode of Action against Melanotic Melanoma Cells than against Normal Human Melanocytes

“…Most cases of de novo melanoma derive from epidermal melanocytes and it causes up to 80% of deaths in the patient suffering from skin cancer [ 2 ]. Melanoma is a type of skin cancer characterised by the high mortality rate, and unsuccessful therapy, which does not give satisfactory effects; in the 4th stage of clinical advancement, therapy does not give sufficient effects—the average life expectancy is 6–10 months, and less than 10% of patients survive 5 years [ 3 , 4 , 5 ]. Despite the beneficial reaction after the use of tyrosinase kinase inhibitors (e.g., dabrafenib, vemurafenib) or immune checkpoint inhibitors (e.g., ipilimumab, nivolumab), these new drugs have failed to provide adequate therapeutic effects in terms of stopping disease progression and considerably extending the life of patients with advanced metastases [ 6 , 7 ].…”