Blue corn is a cereal rich in phenolic compounds used to make blue tortillas. Tortillas are an important part of the Mexican diet. Blue corn and tortilla represent an important source of the natural antioxidants anthocyanins. However, studies on their biological activity on cancer cell lines are limited. The goal of this study was to evaluate the antioxidant and antiproliferative activity of blue corn and tortilla on different cancer cell lines. Total polyphenol content, monomeric anthocyanins, and antioxidant activity by the DPPH and TBARS methods of blue corn and tortilla were determined. The anthocyanin profile of tortilla was obtained by means of HPLC–ESI-MS. The antiproliferative activity of blue corn and tortilla extract on HepG2, H-460, Hela, MCF-7 and PC-3 was evaluated by the MTT assay. Blue corn had higher content of total polyphenols and monomeric anthocyanins as well as lower percentage of polymeric color than tortilla; however, both showed similar antioxidant activity by DPPH. In addition, although a higher degradation of anthocyanins was observed on tortilla extract, both extracts inhibited lipid peroxidation (IC50) at a similar concentration. The anthocyanin profile showed 28 compounds which are primarily derived from cyanidin, including acylated anthocyanins and proanthocyanidins. Blue corn and tortilla extracts showed antiproliferative effects against HepG2, H-460, MCF-7 and PC-3 cells at 1000 μg/mL, however Hela cells were more sensitive at this concentration. This is the first report to demonstrate anticancer properties in vitro of tortilla derived from blue corn, suggesting that this product has beneficial health effects. In addition, blue corn could be a potential source of nutraceuticals with anticancer activity.
Despite of the capacity that several drugs have for specific inhibition of the androgen receptor (AR), in most cases, PCa progresses to an androgen-independent stage. In this context, the development of new targeted therapies for prostate cancer (PCa) has remained as a challenge. To overcome this issue, new tools, based on nucleic acids technology, have been developed. Aptamers are small oligonucleotides with a three-dimensional structure capable of interacting with practically any desired target, even large targets such as mammalian cells or viruses. Recently, aptamers have been studied for treatment and detection of many diseases including cancer. In PCa, numerous works have reported their use in the development of new approaches in diagnostics and treatment strategies. Aptamers have been joined with drugs or other specific molecules such as silencing RNAs (aptamer–siRNA chimeras) to specifically reduce the expression of oncogenes in PCa cells. Even though these studies have shown good results in the early stages, more research is still needed to demonstrate the clinical value of aptamers in PCa. The aim of this review was to compile the existing scientific literature regarding the use of aptamers in PCa in both diagnosis and treatment studies. Since Prostate-Specific Membrane Antigen (PSMA) aptamers are the most studied type of aptamers in this field, special emphasis was given to these aptamers.
Background: Prostate cancer (PCa) is the second cause of cancer related death in North American men. Androgens play an important role in its progression by regulating the expression of several genes including fusion ones that results from structural chromosome rearrangements. TMPRSS2-ERG is a fusion gene commonly observed in over 50% of PCa tumors, and its expression can be transcriptionally regulated by the androgen receptor (AR) given its androgen responsive elements. TMPRSS2-ERG could be involved in epithelial–mesenchymal transition (EMT) during tumor development. ERG has been reported as a key transcriptional factor in the AR-ERG-WNT network where five SFRP proteins, structurally similar to WNT ligands and considered to be WNT pathway antagonists, can regulate signaling in the extracellular space by binding to WNT proteins or Frizzled receptors. It has been shown that over-expression of SFRP1 protein can regulate the transcriptional activity of AR and inhibits the formation of colonies in LNCaP cells. However, the effect of SFRP1 has been controversial since differential effects have been observed depending on its concentration and tissue location. In this study, we explored the role of exogenous SFRP1 protein in cells expressing the TMPRSS2-ERG fusion. Methods: To evaluate the effect of exogenous SFRP1 protein on PCa cells expressing TMPRSS2-ERG, we performed in silico analysis from TCGA cohort, expression assays by RT-qPCR and Western blot, cell viability and cell cycle measurements by cytometry, migration and invasion assays by xCELLigance system and murine xenografts. Results: We demonstrated that SFRP1 protein increased ERG expression by promoting cellular migration in vitro and increasing tumor growth in vivo in PCa cells with the TMPRSS2-ERG fusion. Conclusions: These results suggest the possible role of exogenous SFRP1 protein as a modulator of AR-ERG-WNT signaling network in cells positive to TMPRSS2-ERG. Further, investigation is needed to determine if SFRP1 protein could be a target in against this type of PCa.
Prostate adenocarcinoma resistance to androgen receptor (AR) signaling inhibitor therapy is associated with elevated glutamine (L-Gln). Glutamine sensors, present in conserved riboswitches (glnA), control nitrogen metabolism in many organisms, such as cyanobacteria. Iterative in silico modifications of glnA found in Synechococcus elongatus and thermodynamic analysis of a 56mer aptamer resulted in high L-Gln specificity and affinity. The optimized aptamer depleted L-Gln from prostate adenocarcinoma cells by both L-Gln sequestration and extracellular glutaminase activation, serving as an allosteric activator. Glutamine depletion reduced FOXM1 transcriptional occupancy on the promoter of FGF8, a known mediator of prostate adenocarcinoma castration resistance. A point mutation in the binding pocket of the 56mer rendered the aptamer ineffective in L-Gln binding and FGF8 regulation. Accordingly, the L-Gln–depleting aptamer, with demonstrated serum stability, limited the proliferation and promoted cell death of castration-resistant prostate adenocarcinoma alone and in combination therapy with AR antagonists, enzalutamide and apalutamide, in subcutaneous and orthotopic mouse models. Further selective tumor targeting was achieved by functionalizing gold nanoparticles with either the optimized L-Gln aptamer or the point-mutant aptamer. Castration sensitivity was restored by the L-Gln–depleting aptamer but not by the point-mutant aptamer. The functionalized nanoparticle demonstrated superior antitumor efficacy in an orthotopic prostate adenocarcinoma model compared with the untargeted aptamer. The antitumor activity of the aptamer helped support L-Gln as an oncometabolite in prostate adenocarcinoma that can be targeted to sensitize tumors to hormone therapy. Significance: Depletion of glutamine, which can mediate hormone therapy resistance in prostate cancer patients, with a cyanobacteria-derived catalytic aptamer blocks FGF8 expression and sensitizes hormone refractive prostate tumors to androgen receptor inhibitors.
Background: Cancer-associated cachexia is a multifactorial metabolic syndrome characterized by progressive skeletal muscle and/or adipose tissue loss and affects approximately 40% of patients with non-small cell lung cancer (NSCLC). However, reliable circulating biomarkers for early detection and risk stratification remain undefined. Based on prior observations linking elevated circulating mitochondrial DNA (mtDNA) to cachexia, we hypothesized that mtDNA and inflammatory protein levels in plasma could predict cachexia onset and trajectories. Methods: We evaluated 27 patients with stage IV NSCLC enrolled in the SeroNet-CORALE cohort with plasma samples collected between 2020 and 2023. Forty biomarkers were quantified at two timepoints (T1 and T2) using a multiplexed MesoScale Discovery platform. Associations between log2-transformed biomarker levels and cachexia status were assessed using Firth’s penalized logistic regression. Results: Among 27 patients (65% female; mean age 65 ± 10 years; 89% adenocarcinoma histology), cachectic patients exhibited lower body mass index at both time points (T1: 21.0 ± 2.0 vs. 27.0 ± 7.0; T2: 21.8 ± 4.9 vs. 25.2 ± 4.9). At T1, cachexia was strongly associated with elevated GDF15 (OR 4.29; 95% CI 1.04–29.74; p = 0.044) and IL-15 (OR 43.83; 95% CI 2.39–>999; p = 0.007), whereas IL-4 had a protective association (OR 0.09; 95% CI 0.00–0.66; p = 0.013). At T2, cachexia was associated with higher mtDNA levels (OR 2.13; 95% CI 1.07–7.69; p = 0.022) and lower levels of IL-15, IL12/IL23p40, and MDC. Conclusions: Distinct inflammatory and mitochondrial biomarkers tracked cachexia evolution in advanced NSCLC, with early GDF-15/IL-15 elevations and later increases in circulating mtDNA. Larger longitudinal studies are warranted to validate these findings and define their clinical relevance.