Alpha-lipoic acid alters the antitumor effect of bortezomib in melanoma cells in vitro

Bortezomib-induced peripheral neuropathy: Clinical features, molecular basis, and therapeutic approach

Bortezomib is the first-line standard and most effective chemotherapeutic for multiple myeloma; however, bortezomib-induced peripheral neuropathy (BIPN) severely affects the chemotherapy regimen and has long-term impact on patients under maintenance therapy. The pathogenesis of BIPN is poorly understood, and basic research and development of BIPN management drugs are in early stages. Besides chemotherapy dose reduction and regimen modification, no recommended prevention and treatment approaches are available for BIPN apart from the International Myeloma Working Group guidelines for peripheral neuropathy in myeloma. An in-depth exploration of the pathogenesis of BIPN, development of additional therapeutic approaches, and identification of risk factors are needed. Optimizing effective and standardized BIPN treatment plans and providing more decision-making evidence for clinical diagnosis and treatment of BIPN are necessary. This article reviews the recent advances in BIPN research; provides an overview of clinical features, underlying molecular mechanisms, and therapeutic approaches; and highlights areas for future studies.

Cardioprotective Effect of Centaurea castriferrei Borbás & Waisb Extract against Doxorubicin-Induced Cardiotoxicity in H9c2 Cells

Doxorubicin (DOX) is one of the most used chemotherapeutic agents in the treatment of various types of cancer. However, a continual problem that is associated with its application in therapeutic regimens is the development of dose-dependent cardiotoxicity. The progression of this process is associated with a range of different mechanisms, but especially with the high level of oxidative stress. The aim of the study was to evaluate the effects of the water and methanol-water extracts from the plant Centaurea castriferrei (CAS) obtained by the ultrasound-assisted extraction method on the DOX-induced cardiotoxicity in the rat embryonic cardiomyocyte cell line H9c2. The H9c2 cells were treated for 48 h with the DOX and water or methanol-water extracts, or a combination (DOX + CAS H₂O/CAS MeOH). The MTT assay, cell cycle analysis, and apoptosis detection revealed that both the tested extracts significantly abolished the cytotoxic effect caused by DOX. Moreover, the detection of oxidative stress by the CellROX reagent, the evaluation of the number of AP sites, and the expressions of the genes related to the oxidative stress defense showed substantial reductions in the oxidative stress levels in the H9c2 cells treated with the combination of DOX and CAS H₂O/CAS MeOH compared with the DOX administered alone. The tested extracts did not affect the cytotoxic effect of DOX on the MCF-7 breast cancer cell line. The obtained results constitute the basis for further research in the context of the application of C. castriferrei extracts as adjuvants in the therapy regiments of cancer patients treated with DOX.

Bortezomib advanced mechanisms of action in multiple myeloma, solid and liquid tumors along with its novel therapeutic applications

Bortezomib (BTZ) is a first-in-class reversible and selective proteasome inhibitor. It inhibits the ubiquitin proteasome pathway that leads to the degradation of many intracellular proteins. Initially, BTZ was FDA approved for the treatment of refractory or relapsed multiple myeloma (MM) in 2003. Later, its usage was approved for patients with previously untreated MM. In 2006, BTZ was approved for the treatment of relapsed or refractory Mantle Cell Lymphoma (MCL) and, in 2014, for previously untreated MCL. BTZ has been extensively studied either alone or in combination with other drugs for the treatment of different liquid tumors especially in MM. However, limited data evaluated the efficacy and safety of using BTZ in patients with solid tumors. In this review, we will discuss the advanced and novel mechanisms of action of BTZ documented in MM, solid tumors and liquid tumors. Moreover, we will shed the light on the newly discovered pharmacological effects of BTZ in other prevalent diseases.

Molecular Markers and Targets in Melanoma

Melanoma develops as a result of several genetic alterations, with UV radiation often acting as a mutagenic risk factor. Deep knowledge of the molecular signaling pathways of different types of melanoma allows better characterization and provides tools for the development of therapies based on the intervention of signals promoted by these cascades. The latest World Health Organization classification acknowledged the specific genetic drivers leading to melanoma and classifies melanocytic lesions into nine distinct categories according to the associate cumulative sun damage (CSD), which correlates with the molecular alterations of tumors. The largest groups are melanomas associated with low-CSD or superficial spreading melanomas, characterized by frequent presentation of the BRAFV600 mutation. High-CSD melanomas include lentigo maligna type and desmoplastic melanomas, which often have a high mutation burden and can harbor NRAS, BRAFnon-V600E, or NF1 mutations. Non-CSD-associated melanomas encompass acral and mucosal melanomas that usually do not show BRAF, NRAS, or NF1 mutations (triple wild-type), but in a subset may have KIT or SF3B1 mutations. To improve survival, these driver alterations can be treated with targeted therapy achieving significant antitumor activity. In recent years, relevant improvement in the prognosis and survival of patients with melanoma has been achieved, since the introduction of BRAF/MEK tyrosine kinase inhibitors and immune checkpoint inhibitors. In this review, we describe the current knowledge of molecular pathways and discuss current and potential therapeutic targets in melanoma, focusing on their clinical relevance of development.

The Synergistic Activity of Bortezomib and TIC10 against A2058 Melanoma Cells

Combination antitumor treatments are essential parts of modern tumor therapy as—compared to monotherapies—(i) they are more effective; (ii) the dose of the compounds can be reduced; and (iii) therefore the side effects are improved. Our research group previously demonstrated the antitumor character of bortezomib (BOZ) in A2058 melanoma cells. Unfortunately, dose-related side effects are common during BOZ therapy, which could be prevented by reducing the dose of BOZ. This study aimed to characterize synergistic combinations of BOZ with a TRAIL (TNF-related apoptosis-inducing ligand) -inducing compound (TIC10), where the doses can be cut down but the efficacy is preserved. Endpoint cell viability assays were performed on A2058 cells, and synergism of BOZ and TIC10 was observed after 72 h. Synergism was further validated in a real-time impedimetric assay, and our results showed that BOZ-treated melanoma cells survived the treatment, an effect not registered in the co-treatments. Treatment with the combinations resulted in increased apoptosis, which was not accompanied by enhanced LDH release. Nevertheless, the expression of death receptor 5 (DR5) was increased on the cell surface without transcriptional regulation. In summary, our findings support the theory that the application of BOZ and TIC10 in combination could provide higher efficacy in vitro.

Aloysia Citrodora Essential Oil Inhibits Melanoma Cell Growth and Migration by Targeting HB-EGF-EGFR Signaling

Patients diagnosed with melanoma have a poor prognosis due to regional invasion and metastases. The receptor tyrosine kinase epidermal growth factor receptor (EGFR) is found in a subtype of melanoma with a poor prognosis and contributes to drug resistance. Aloysia citrodora essential oil (ALOC-EO) possesses an antitumor effect. Understanding signaling pathways that contribute to the antitumor of ALOC-EO is important to identify novel tumor types that can be targeted by ALOC-EO. Here, we investigated the effects of ALOC-EO on melanoma growth and tumor cell migration. ALOC-EO blocked melanoma growth in vitro and impaired primary tumor cell growth in vivo. Mechanistically, ALOC-EO blocked heparin-binding-epidermal growth factor (HB-EGF)-induced EGFR signaling and suppressed ERK1/2 phosphorylation. Myelosuppressive drugs upregulated HB-EGF and EGFR expression in melanoma cells. Cotreatment of myelosuppressive drugs with ALOC-EO improved the antitumor activity and inhibited the expression of matrix metalloproteinase-7 and -9 and a disintegrin and metalloproteinase domain-containing protein9. In summary, our study demonstrates that ALOC-EO blocks EGFR and ERK1/2 signaling, with preclinical efficacy as a monotherapy or in combination with myelosuppressive drugs in melanoma.

Pathological Mechanisms of Bortezomib-Induced Peripheral Neuropathy

Bortezomib, a first-generation proteasome inhibitor widely used in chemotherapy for hematologic malignancy, has effective anti-cancer activity but often causes severe peripheral neuropathy. Although bortezomib-induced peripheral neuropathy (BIPN) is a dose-limiting toxicity, there are no recommended therapeutics for its prevention or treatment. One of the most critical problems is a lack of knowledge about pathological mechanisms of BIPN. Here, we summarize the known mechanisms of BIPN based on preclinical evidence, including morphological abnormalities, involvement of non-neuronal cells, oxidative stress, and alterations of transcriptional programs in both the peripheral and central nervous systems. Moreover, we describe the necessity of advancing studies that identify the potential efficacy of approved drugs on the basis of pathological mechanisms, as this is a convincing strategy for rapid translation to patients with cancer and BIPN.