Improving therapeutic potential in breast cancer via histone deacetylase inhibitor loaded nanofibrils

Epigenetic modifications play a significant role in cancer progression, making them potential targets for therapy. Histone deacetylase inhibitors have shown promise in inhibiting cancer cell growth, including in breast cancer (BC). In this research, we examined the potential of using suberoyl anilide hydroxamic acid (SAHA)-loaded β-lg nanofibrils as a drug delivery system for triple-negative BC cell lines. We assessed their impact on cell cycle progression, apoptosis, levels of reactive oxygen species, and mitochondrial membrane potential in cancer cells. The combination of SAHA and β-lg nanofibrils demonstrated enhanced efficacy in inhibiting cell growth, inducing cell cycle arrest, and promoting apoptosis (43.78%) compared to SAHA alone (40.09%). Moreover, it effectively targeted cancer cells without promoting drug resistance while using a low concentration of the nanofibrils. These findings underscore the promising potential of nanofibril-based drug delivery systems for BC treatment.

Utilizing protein nanofibrils as a scaffold for enhancing nutritional value in toned milk

Toned milk is a lower-fat, healthier alternative to whole milk that still contains all essential nutrients. A number of methods have been developed to improve the functionality of toned milk and make it more appealing to the consumers. However, these methods often involve extensive processing techniques and can be expensive. Therefore, alternative methods are needed. Proteins are well known for their ability to form well-defined nanofibril materials that can be used as a scaffold for various applications. In this article, a straightforward self-assembly process was used to load inulin into protein nanofibrils, creating unique composite nanofibrils. Characterization using AFM and SEM revealed well-defined composite nanofibrils with an average diameter of 4-6 nm and lengths ranging from 0.25 μm up to 10 μm. FT-IR and in-vitro release assays show that inulin was successfully attached to prepared protein nanofibrils. The composite nanofibrils were tested on toned milk to enhance the physico/chemical properties and nutritional values. The findings can be applied to the food industry to create a number of novel functional food products cost-effectively.

Recent development in preparation of food packaging films using biopolymers

In the past decades, most materials used in the food packaging industry are nonbiodegradable materials that pose increased environmental concerns and sustainability issues. Hence, polymer-based biodegradable materials and edible films have been developed to increase the shelf life of food products. Especially, biopolymer-based nanomaterials are engineered with multifunctional characteristics because of their size, surface area, shelf life, thermal stability, and mechanical and barrier strength. These materials display enriched properties of biodegradability, antimicrobial activity, and biocompatibility and may have the possibility to replace plastic materials in future. Thus, this review offers a brief overview of the classification of biopolymers, key parameters that are important in food packaging films (including the role of plasticizers, cross-linkers, pH, temperature, and relative humidity), and recent applications of novel biopolymer nanocomposite materials used in the food industries.

Inhibition of WNT-CTNNB1 signaling upregulates SQSTM1 and sensitizes glioblastoma cells to autophagy blockers

WNT-CTNN1B signaling promotes cancer cell proliferation and stemness. Furthermore, recent evidence indicates that macroautophagy/autophagy regulates WNT signaling. Here we investigated the impact of inhibiting WNT signaling on autophagy in glioblastoma (GBM), a devastating brain tumor. Inhibiting TCF, or silencing TCF4 or CTNNB1/β-catenin upregulated SQSTM1/p62 in GBM at transcriptional and protein levels and, in turn, autophagy. DKK1/Dickkopf1, a canonical WNT receptor antagonist, also induced autophagic flux. Importantly, TCF inhibition regulated autophagy through MTOR inhibition and dephosphorylation, and nuclear translocation of TFEB, a master regulator of lysosomal biogenesis and autophagy. TCF inhibition or silencing additionally affected GBM cell proliferation and migration. Autophagy induction followed by its blockade can promote cancer cell death. In agreement with this notion, halting both TCF-CTNNB1 and autophagy pathways decreased cell viability and induced apoptosis of GBM cells through a SQSTM1-dependent mechanism involving CASP8 (caspase 8). In vivo experiments further underline the therapeutic potential of such dual targeting in GBM.

Voltage-gated calcium channel blockers deregulate macroautophagy in cardiomyocytes

Voltage-gated calcium channel blockers are widely used for the management of cardiovascular diseases, however little is known about their effects on cardiac cells in vitro. We challenged neonatal ventricular cardiomyocytes (CMs) with therapeutic L-type and T-type Ca(2+) channel blockers (nifedipine and mibefradil, respectively), and measured their effects on cell stress and survival, using fluorescent microscopy, Q-PCR and Western blot. Both nifedipine and mibefradil induced a low-level and partially transient up-regulation of three key mediators of the Unfolded Protein Response (UPR), indicative of endoplasmic (ER) reticulum stress. Furthermore, nifedipine triggered the activation of macroautophagy, as evidenced by increased lipidation of microtubule-associated protein 1 light chain 3 (LC3), decreased levels of polyubiquitin-binding protein p62/SQSTM1 and ubiquitinated protein aggregates, that was followed by cell death. In contrast, mibefradil inhibited CMs constitutive macroautophagy and did not promote cell death. The siRNA-mediated gene silencing approach confirmed the pharmacological findings for T-type channels. We conclude that L-type and T-type Ca(2+) channel blockers induce ER stress, which is divergently transduced into macroautophagy induction and inhibition, respectively, with relevance for cell viability. Our work identifies VGCCs as novel regulators of autophagy in the heart muscle and provides new insights into the effects of VGCC blockers on CMs homeostasis, that may underlie both noxious and cardioprotective effects.

T-type calcium channel blockers inhibit autophagy and promote apoptosis of malignant melanoma cells

We have recently reported that human melanoma cells express a variety of voltage-gated calcium (Ca(2+) ) channel types, including low-voltage-activated T-type channels that play a significant role in melanoma cell cycle progression. Here, we challenged melanoma metastatic cells with T-type channel blockers of clinical use and found a dual effect on cell viability: (i) a reduction in the proliferation rate, through a halt in the progression to the G1 -S phase; and (ii) a promotion of cell death that was partially dependent on the activation of caspases. An in-depth analysis of the death process showed that the apoptotic pathway is preceded by endoplasmic reticulum stress and the subsequent inhibition of the basal macroautophagy which is active in these cells. The effects of pharmacological blockers on Ca(2+) homeostasis, autophagy, and cell death were mimicked by T-type channel gene silencing. These results provide the basis for a new pharmacological and/or gene silencing approach toward tackling melanoma metastasis.

Functional expression of voltage-gated calcium channels in human melanoma

The expression of voltage-gated calcium channels (VGCCs) has not been reported previously in melanoma cells in spite of increasing evidence of a role of VGCCs in tumorigenesis and tumour progression. To address this issue we have performed an extensive RT-PCR analysis of VGCC expression in human melanocytes and a range of melanoma cell lines and biopsies. In addition, we have tested the functional expression of these channels using Ca(2+) imaging techniques and examined their relevance for the viability and proliferation of the melanoma cells. Our results show that control melanocytes and melanoma cells express channel isoforms belonging to the Ca(v) 1 and Ca(v) 2 gene families. Importantly, the expression of low voltage-activated Ca(v) 3 (T-type) channels is restricted to melanoma. We have confirmed the function of T-type channels as mediators of constitutive Ca(2+) influx in melanoma cells. Finally, pharmacological and gene silencing approaches demonstrate a role for T-type channels in melanoma viability and proliferation. These results encourage the analysis of T-type VGCCs as targets for therapeutic intervention in melanoma tumorigenesis and/or tumour progression.