Bcl-2 family proteins and cytoskeleton changes involved in DM-1 cytotoxic effect on melanoma cells

The Role of Nutraceuticals and Functional Foods in Skin Cancer: Mechanisms and Therapeutic Potential

Skin cancer is a prevalent type of cancer worldwide and has a high growth rate compared to other diseases. Although modern targeted therapies have improved the management of cutaneous neoplasms, there is an urgent requirement for a safer, more affordable, and effective chemoprevention and treatment strategy for skin cancer. Nutraceuticals, which are natural substances derived from food, have emerged as a potential alternative or adjunctive treatment option. In this review, we explore the current evidence on the use of omega-3 fatty acids and polyphenols (curcumin, epigallocatechin gallate, apigenin, resveratrol, and genistein) for the treatment of melanoma and non-melanoma skin cancer (NMSC), as well as in their prevention. We discuss the mechanisms of action of the aforementioned nutraceuticals and their probable therapeutic benefits in skin cancer. Omega-3 fatty acids, curcumin, epigallocatechin gallate, apigenin, resveratrol, and genistein have several properties, among which are anti-inflammatory and anti-tumor, which can help to prevent and treat skin cancer. However, their effectiveness is limited due to poor bioavailability. Nanoparticles and other delivery systems can improve their absorption and targeting. More research is needed to evaluate their safety and effectiveness as a natural approach to skin cancer prevention and treatment. These compounds should not replace conventional cancer treatments, but may be used as complementary therapy under the guidance of a healthcare professional.

HDAC11 activity contributes to MEK inhibitor escape in uveal melanoma

We previously demonstrated that pan-HDAC inhibitors could limit escape from MEK inhibitor (MEKi) therapy in uveal melanoma (UM) through suppression of AKT and YAP/TAZ signaling. Here, we focused on the role of specific HDACs in therapy adaptation. Class 2 UM displayed higher expression of HDACs 1, 2, and 3 than Class 1, whereas HDACs 6, 8, and 11 were uniformly expressed. Treatment of UM cells with MEKi led to modulation of multiple HDACs, with the strongest increases observed in HDAC11. RNA-seq analysis showed MEKi to decrease the expression of multiple HDAC11 target genes. Silencing of HDAC11 significantly reduced protein deacetylation, enhanced the apoptotic response to MEKi and reduced growth in long-term colony formation assays across multiple UM cell lines. Knockdown of HDAC11 led to decreased expression of TAZ in some UM cell lines, accompanied by decreased YAP/TAZ transcriptional activity and reduced expression of multiple YAP/TAZ target genes. Further studies showed this decrease in TAZ expression to be associated with increased LKB1 activation and modulation of glycolysis. In an in vivo model of uveal melanoma, silencing of HDAC11 limited the escape to MEKi therapy, an effect associated with reduced levels of Ki67 staining and increased cleaved caspase-3. We have demonstrated a novel role for adaptive HDAC11 activity in UM cells, that in some cases modulates YAP/TAZ signaling leading to MEKi escape.

Diarylpentanoid (1,5-bis(4-hydroxy-3-methoxyphenyl)-1,4-pentadiene-3-one) (MS13) Exhibits Anti-proliferative, Apoptosis Induction and Anti-migration Properties on Androgen-independent Human Prostate Cancer by Targeting Cell Cycle-Apoptosis and PI3K Signalling Pathways

Diarylpentanoids exhibit a high degree of anti-cancer activity and stability in vitro over curcumin in prostate cancer cells. Hence, this study aims to investigate the effects of a diarylpentanoid, 1,5-bis(4-hydroxy-3-methoxyphenyl)-1,4-pentadiene-3-one (MS13) on cytotoxicity, anti-proliferative, apoptosis-inducing, anti-migration properties, and the underlying molecular mechanisms on treated androgen-independent prostate cancer cells, DU 145 and PC-3. A cell viability assay has shown greater cytotoxicity effects of MS13-treated DU 145 cells (EC₅₀ 7.57 ± 0.2 µM) and PC-3 cells (EC₅₀ 7.80 ± 0.7 µM) compared to curcumin (EC₅₀: DU 145; 34.25 ± 2.7 µM and PC-3; 27.77 ± 6.4 µM). In addition, MS13 exhibited significant anti-proliferative activity against AIPC cells compared to curcumin in a dose- and time-dependent manner. Morphological observation, increased caspase-3 activity, and reduced Bcl-2 protein levels in these cells indicated that MS13 induces apoptosis in a time- and dose-dependent. Moreover, MS13 effectively inhibited the migration of DU 145 and PC-3 cells. Our results suggest that cell cycle-apoptosis and PI3K pathways were the topmost significant pathways impacted by MS13 activity. Our findings suggest that MS13 may demonstrate the anti-cancer activity by modulating DEGs associated with the cell cycle-apoptosis and PI3K pathways, thus inhibiting cell proliferation and cell migration as well as inducing apoptosis in AIPC cells.

Molecular Mechanisms of Antiproliferative and Apoptosis Activity by 1,5-Bis(4-Hydroxy-3-Methoxyphenyl)1,4-Pentadiene-3-one (MS13) on Human Non-Small Cell Lung Cancer Cells

Diarylpentanoid (DAP), an analog that was structurally modified from a naturally occurring curcumin, has shown to enhance anticancer efficacy compared to its parent compound in various cancers. This study aims to determine the cytotoxicity, antiproliferative, and apoptotic activity of diarylpentanoid MS13 on two subtypes of non-small cell lung cancer (NSCLC) cells: squamous cell carcinoma (NCI-H520) and adenocarcinoma (NCI-H23). Gene expression analysis was performed using Nanostring PanCancer Pathways Panel to determine significant signaling pathways and targeted genes in these treated cells. Cytotoxicity screening revealed that MS13 exhibited greater inhibitory effect in NCI-H520 and NCI-H23 cells compared to curcumin. MS13 induced anti-proliferative activity in both cells in a dose- and time-dependent manner. Morphological analysis revealed that a significant number of MS13-treated cells exhibited apoptosis. A significant increase in caspase-3 activity and decrease in Bcl-2 protein concentration was noted in both MS13-treated cells in a time- and dose-dependent manner. A total of 77 and 47 differential expressed genes (DEGs) were regulated in MS13 treated-NCI-H520 and NCI-H23 cells, respectively. Among the DEGs, 22 were mutually expressed in both NCI-H520 and NCI-H23 cells in response to MS13 treatment. The top DEGs modulated by MS13 in NCI-H520—DUSP4, CDKN1A, GADD45G, NGFR, and EPHA2—and NCI-H23 cells—HGF, MET, COL5A2, MCM7, and GNG4—were highly associated with PI3K, cell cycle-apoptosis, and MAPK signaling pathways. In conclusion, MS13 may induce antiproliferation and apoptosis activity in squamous cell carcinoma and adenocarcinoma of NSCLC cells by modulating DEGs associated with PI3K-AKT, cell cycle-apoptosis, and MAPK pathways. Therefore, our present findings could provide an insight into the anticancer activity of MS13 and merits further investigation as a potential anticancer agent for NSCLC cancer therapy.

Metalloproteinases Suppression Driven by the Curcumin Analog DM-1 Modulates Invasion in BRAF-Resistant Melanomas

BACKGROUND

Melanoma is the most aggressive skin cancer, and BRAF (V600E) is the most frequent mutation that led to the development of BRAF inhibitors (BRAFi). However, patients treated with BRAFi usually present recidivism after 6-9 months. Curcumin is a turmeric substance, and it has been deeply investigated due to its anti-inflammatory and antitumoral effects. Still, the low bioavailability and biodisponibility encouraged the investigation of different analogs. DM-1 is a curcumin analog and has shown an antitumoral impact in previous studies.

METHODS

Evaluated DM-1 stability and cytotoxic effects for BRAFi-sensitive and resistant melanomas, as well as the role in the metalloproteinases modulation.

RESULTS

DM-1 showed growth inhibitory potential for melanoma cells, demonstrated by reduction of colony formation, migration and endothelial tube formation, and cell cycle arrest. Subtoxic doses were able to downregulate important Metalloproteinases (MMPs) related to invasiveness, such as MMP-1, -2 and -9. Negative modulations of TIMP-2 and MMP-14 reduced MMP-2 and -9 activity; however, the reverse effect is seen when increased TIMP-2 and MMP-14 resulted in raised MMP-2.

CONCLUSION

These findings provide essential details into the functional role of DM-1 in melanomas, encouraging further studies in the development of combinatorial treatments for melanomas.

Proteomic Analysis on Anti-Proliferative and Apoptosis Effects of Curcumin Analog, 1,5-bis(4-Hydroxy-3-Methyoxyphenyl)-1,4-Pentadiene-3-One-Treated Human Glioblastoma and Neuroblastoma Cells

Curcumin analogs with excellent biological properties have been synthesized to address and overcome the poor pharmacokinetic profiles of curcumin. This study aims to investigate the cytotoxicity, anti-proliferative, and apoptosis-inducing ability of curcumin analog, MS13 on human glioblastoma U-87 MG, and neuroblastoma SH-SY5Y cells, and to examine the global proteome changes in these cells following treatment. Our current findings showed that MS13 induced potent cytotoxicity and anti-proliferative effects on both cells. Increased caspase-3 activity and decreased bcl-2 concentration upon treatment indicate that MS13 induces apoptosis in these cells in a dose- and time-dependent manner. The label-free shotgun proteomic analysis has defined the protein profiles in both glioblastoma and neuroblastoma cells, whereby a total of nine common DEPs, inclusive of glyceraldehyde 3-phosphate dehydrogenase (GAPDH), alpha-enolase (ENO1), heat shock protein HSP 90-alpha (HSP90AA1), Heat shock protein HSP 90-beta (HSP90AB1), Eukaryotic translation initiation factor 5A-1 (EFI5A), heterogenous nuclear ribonucleoprotein K (HNRNPK), tubulin beta chain (TUBB), histone H2AX (H2AFX), and Protein SET were identified. Pathway analysis further elucidated that MS13 may induce its anti-tumor effects in both cells via the common enriched pathways, “Glycolysis” and “Post-translational protein modification.” Conclusively, MS13 demonstrates an anti-cancer effect that may indicate its potential use in the management of brain malignancies.

Unraveling the molecular mechanisms and the potential chemopreventive/therapeutic properties of natural compounds in melanoma

Melanoma is the most fatal form of skin cancer. Current therapeutic approaches include surgical resection, chemotherapy, targeted therapy and immunotherapy. However, these treatment strategies are associated with development of drug resistance and severe side effects. In recent years, natural compounds have also been extensively studied for their anti-melanoma effects, including tumor growth inhibition, apoptosis induction, angiogenesis and metastasis suppression and cancer stem cell elimination. Moreover, a considerable number of studies reported the synergistic activity of phytochemicals and standard anti-melanoma agents, as well as the enhanced effectiveness of their synthetic derivatives and novel formulations. However, clinical data confirming these promising effects in patients are still scanty. This review emphasizes the anti-tumor mechanisms and potential application of the most studied natural products for melanoma prevention and treatment.

HDAC Inhibition Enhances the In Vivo Efficacy of MEK Inhibitor Therapy in Uveal Melanoma

PURPOSE

The clinical use of MEK inhibitors in uveal melanoma is limited by the rapid acquisition of resistance. This study has used multiomics approaches and drug screens to identify the pan-HDAC inhibitor panobinostat as an effective strategy to limit MEK inhibitor resistance.Experimental Design: Mass spectrometry-based proteomics and RNA-Seq were used to identify the signaling pathways involved in the escape of uveal melanoma cells from MEK inhibitor therapy. Mechanistic studies were performed to evaluate the escape pathways identified, and the efficacy of the MEK-HDAC inhibitor combination was demonstrated in multiple in vivo models of uveal melanoma.

RESULTS

We identified a number of putative escape pathways that were upregulated following MEK inhibition, including the PI3K/AKT pathway, ROR1/2, and IGF-1R signaling. MEK inhibition was also associated with increased GPCR expression, particularly the endothelin B receptor, and this contributed to therapeutic escape through ET-3-mediated YAP signaling. A screen of 289 clinical grade compounds identified HDAC inhibitors as potential candidates that suppressed the adaptive YAP and AKT signaling that followed MEK inhibition. In vivo, the MEK-HDAC inhibitor combination outperformed either agent alone, leading to a long-term decrease of tumor growth in both subcutaneous and liver metastasis models and the suppression of adaptive PI3K/AKT and YAP signaling.

CONCLUSIONS

Together, our studies have identified GPCR-mediated YAP activation and RTK-driven AKT signaling as key pathways involved in the escape of uveal melanoma cells from MEK inhibition. We further demonstrate that HDAC inhibition is a promising combination partner for MEK inhibitors in advanced uveal melanoma.

Toxicogenomic and bioinformatics platforms to identify key molecular mechanisms of a curcumin-analogue DM-1 toxicity in melanoma cells

Melanoma is a highly invasive and metastatic cancer with high mortality rates and chemoresistance. Around 50% of melanomas are driven by activating mutations in BRAF that has led to the development of potent anti-BRAF inhibitors. However resistance to anti-BRAF therapy usually develops within a few months and consequently there is a need to identify alternative therapies that will bypass BRAF inhibitor resistance. The curcumin analogue DM-1 (sodium 4-[5-(4-hydroxy-3-methoxy-phenyl)-3-oxo-penta-1,4-dienyl]-2-methoxy-phenolate) has substantial anti-tumor activity in melanoma, but its mechanism of action remains unclear. Here we use a synthetic lethal genetic screen in Saccharomyces cerevisiae to identify 211 genes implicated in sensitivity to DM-1 toxicity. From these 211 genes, 74 had close human orthologues implicated in oxidative phosphorylation, insulin signaling and iron and RNA metabolism. Further analysis identified 7 target genes (ADK, ATP6V0B, PEMT, TOP1, ZFP36, ZFP36L1, ZFP36L2) with differential expression during melanoma progression implicated in regulation of tumor progression, cell differentiation, and epithelial-mesenchymal transition. Of these TOP1 and ADK were regulated by DM-1 in treatment-naïve and vemurafenib-resistant melanoma cells respectively. These data reveal that the anticancer effect of curcumin analogues is likely to be mediated via multiple targets and identify several genes that represent candidates for combinatorial targeting in melanoma.

Targeting the hedgehog transcription factors GLI1 and GLI2 restores sensitivity to vemurafenib-resistant human melanoma cells

BRAF inhibitor (BRAFi) therapy for melanoma patients harboring the V600E mutation is initially highly effective, but almost all patients relapse within a few months. Understanding the molecular mechanisms underpinning BRAFi-based therapy is therefore an important issue. Here we identified a previously unsuspected mechanism of BRAFi resistance driven by elevated Hedgehog (Hh) pathway activation that is observed in a cohort of melanoma patients after vemurafenib treatment. Specifically, we demonstrate that melanoma cell lines, with acquired in vitro-induced vemurafenib resistance, show increased levels of glioma-associated oncogene homolog 1 and 2 (GLI1/GLI2) compared with naïve cells. We also observed these findings in clinical melanoma specimens. Moreover, the increased expression of the transcription factors GLI1/GLI2 was independent of canonical Hh signaling and was instead correlated with the noncanonical Hh pathway, involving TGFβ/SMAD (transforming growth factor-β/Sma- and Mad-related family) signaling. Knockdown of GLI1 and GLI2 restored sensitivity to vemurafenib-resistant cells, an effect associated with both growth arrest and senescence. Treatment of vemurafenib-resistant cells with the GLI1/GLI2 inhibitor Gant61 led to decreased invasion of the melanoma cells in a three-dimensional skin reconstruct model and was associated with a decrease in metalloproteinase (MMP2/MMP9) expression and microphthalmia transcription factor upregulation. Gant61 monotherapy did not alter the drug sensitivity of naïve cells, but could reverse the resistance of melanoma cells chronically treated with vemurafenib. We further noted that alternating dosing schedules of Gant61 and vemurafenib prevented the onset of BRAFi resistance, suggesting that this could be a potential therapeutic strategy for the prevention of therapeutic escape. Our results suggest that targeting the Hh pathway in BRAFi-resistant melanoma may represent a viable therapeutic strategy to restore vemurafenib sensitivity, reducing or even inhibiting the acquired chemoresistance in melanoma patients.

Curcumin: A new candidate for melanoma therapy?

Melanoma remains among the most lethal cancers and, in spite of great attempts that have been made to increase the life span of patients with metastatic disease, durable and complete remissions are rare. Plants and plant extracts have long been used to treat a variety of human conditions; however, in many cases, effective doses of herbal remedies are associated with serious adverse effects. Curcumin is a natural polyphenol that shows a variety of pharmacological activities including anti-cancer effects, and only minimal adverse effects have been reported for this phytochemical. The anti-cancer effects of curcumin are the result of its anti-angiogenic, pro-apoptotic and immunomodulatory properties. At the molecular and cellular level, curcumin can blunt epithelial-to-mesenchymal transition and affect many targets that are involved in melanoma initiation and progression (e.g., BCl2, MAPKS, p21 and some microRNAs). However, curcumin has a low oral bioavailability that may limit its maximal benefits. The emergence of tailored formulations of curcumin and new delivery systems such as nanoparticles, liposomes, micelles and phospholipid complexes has led to the enhancement of curcumin bioavailability. Although in vitro and in vivo studies have demonstrated that curcumin and its analogues can be used as novel therapeutic agents in melanoma, curcumin has not yet been tested against melanoma in clinical practice. In this review, we summarized reported anti-melanoma effects of curcumin as well as studies on new curcumin formulations and delivery systems that show increased bioavailability. Such tailored delivery systems could pave the way for enhancement of the anti-melanoma effects of curcumin.

Evaluation of the anti-inflammatory action of curcumin analog (DM1): Effect on iNOS and COX-2 gene expression and autophagy pathways

This work describes the anti-inflammatory effect of the curcumin-analog compound, sodium 4-[5-(4-hydroxy-3-methoxyphenyl)-3-oxo-penta-1,4-dienyl]-2-methoxy-phenolate (DM1), and shows that DM1 modulates iNOS and COX-2 gene expression in cultured RAW 264.7 cells and induces autophagy on human melanoma cell line A375.

Protection effect of trigonelline on liver of rats with non-alcoholic fatty liver diseases

OBJECTIVE

To study the effect of trigonelline on the change of indicators of serum transaminase, lipoprotein and liver lipid of model rats with non-alcoholic fatty liver diseases and on the expression level of Bcl-2 and Bax proteins.

METHODS

A total of 45 SD rats were randomly divided into the control group, model group and trigonelline intervention group. Rats in the control group were fed with the common diet, while rats in the model group and intervention group were fed with the high fat diet. 8 weeks later, the intervention group received the intragastric administration of trigonellin e (with the dosage of 40 mg/kg/d) for 8 weeks; while control group and model group received the intragastric administration of saline with the equal dosage. Blood was taken from the abdominal aorta of rats 8 weeks later, detecting the level of a series of indicators of ALT, AST, TG, TC, HDL-C and LDL-C in the serum. After the rats were sacrificed, detect the indicators of TG, TC, SOD and MDA in the liver tissue of rats, as well as the expression of Bcl-2 and Bax in the liver tissue.

RESULTS

Results of histopathologic examination showed that the damage degree of liver for rats in the trigonelline intervention group was smaller than the one in the model group, with significantly reduced hepatic steatosis and the partially visible hepatic lobule. The levels of ALT, AST, TC and LDL-C in the serum of rats in the trigonelline group were significantly reduced, while the change in the levels of TG and HDL-C was not significantly different. The levels of TG, TC and MDA in the liver tissues were significantly decreased, while the level of SOD significantly increased; the expression of Bcl-2 protein in the liver tissues of rats in the trigonelline intervention group was significantly increased, while the expression of Bax protein significantly decreased.

CONCLUSIONS

The trigonelline contributes to the therapeutic effect of non-alcoholic fatty liver diseases. It can also increase the expression of Bcl-2 protein and decrease the expression of Bax protein in the liver tissues, which can protect the liver.

Curcumin analog DM-1 in monotherapy or combinatory treatment with dacarbazine as a strategy to inhibit in vivo melanoma progression

Malignant melanoma is a highly aggressive form of skin cancer with a high mortality rate if not discovered in early stages. Although a limited number of treatment options for melanoma currently exist, patients with a more aggressive form of this cancer frequently decline treatment. DM-1 is a sodium phenolate and curcumin analog with proven anticancer, anti-proliferative and anti-metastatic properties. In this paper, the DM-1 compound showed in vivo antitumor activity alone or in combination with chemotherapeutic DTIC in B16F10 melanoma-bearing mice. Beneficial effects such as melanoma tumor burden reduction with pyknotic nuclei, decreased nuclei/cytoplasmic ratio and nuclear degradation occurred after DM-1 treatment. No toxicological changes were observed in the liver, kidneys, spleen and lungs after DM-1 monotherapy or DTIC combined therapy. DTIC+DM-1 treatment induced the recovery of anemia arising from melanoma and immunomodulation. Both DM-1 treatment alone and in combination with DTIC induced apoptosis with the cleavage of caspase-3, -8 and -9. Furthermore, melanoma tumors treated with DM-1 showed a preferential apoptotic intrinsic pathway by decreasing Bcl-2/Bax ratio. Considering the chemoresistance exhibited by melanoma towards conventional chemotherapy drugs, DM-1 compound in monotherapy or in combination therapy provides a promising improvement in melanoma treatment with a reduction of side effects.