Plausible role of naringenin against cerebrally implanted C6 glioma cells in rats

The protective roles of citrus flavonoids, naringenin, and naringin on endothelial cell dysfunction in diseases

The endothelial cells (ECs) make up the inner lining of blood vessels, acting as a barrier separating the blood and the tissues in several organs. ECs maintain endothelium integrity by controlling the constriction and relaxation of the vasculature, blood fluidity, adhesion, and migration. These actions of ECs are efficiently coordinated via an intricate signaling network connecting receptors, and a wide range of cellular macromolecules. ECs are naturally quiescent i.e.; they are not stimulated and do not proliferate. Upon infection or disease, ECs become activated, and this alteration is pivotal in the pathogenesis of a spectrum of human neurological, cardiovascular, diabetic, cancerous, and viral diseases. Considering the central position that ECs play in disease pathogenesis, therapeutic options have been targeted at improving ECs integrity, assembly, functioning, and health. The dietary intake of flavonoids present in citrus fruits has been associated with a reduced risk of endothelium dysfunction. Naringenin (NGN) and Naringin (NAR), major flavonoids in grapefruit, tomatoes, and oranges possess anti-inflammatory, antioxidant properties, and cell survival potentials, which improve the health of the vascular endothelium. In this review, we provide a comprehensive summary and present the advances in understanding of the mechanisms through which NGN and NAR modulate the biomarkers of vascular dysfunction and protect the endothelium against unresolved inflammation, oxidative stress, atherosclerosis, and angiogenesis. We also provide perspectives and suggest further studies that will help assess the efficacy of citrus flavonoids in the therapeutics of human vascular diseases.

Targeting the two-pore channel 2 in cancer progression and metastasis

The importance of Ca²⁺ signaling, and particularly Ca²⁺ channels, in key events of cancer cell function such as proliferation, metastasis, autophagy and angiogenesis, has recently begun to be appreciated. Of particular note are two-pore channels (TPCs), a group of recently identified Ca²⁺-channels, located within the endolysosomal system. TPC2 has recently emerged as an intracellular ion channel of significant pathophysiological relevance, specifically in cancer, and interest in its role as an anti-cancer drug target has begun to be explored. Herein, an overview of the cancer-related functions of TPC2 and a discussion of its potential as a target for therapeutic intervention, including a summary of clinical trials examining the TPC2 inhibitors, naringenin, tetrandrine, and verapamil for the treatment of various cancers is provided.

Naringenin Sensitizes Resistant C6 Glioma Cells with a Repressive Impact on the Migrating Ability

Background:

Glioma, the most common form of a malignant brain tumour is characterised by a poor prognosis, which is attributable to its resistance against current therapeutic approaches. Temozolomide (TMZ), a DNA alkylating agent, is the first-line drug for glioma treatment. Long-term treatment using TMZ was reported to culminate in the development of resistance with overexpression of multidrug resistance 1 gene coded protein P-glycoprotein, which in turn releases the drugs from the tumour cells.

Purpose:

Thus, to circumvent such resistance issues, the current study attempted to explore the effect of naringenin (a flavanone) with proven antiglial tumour potential, in mitigating the features of TMZ resistance.

Methods:

Colony-forming assay, invasion assay and scratch wound assay were performed among the groups, namely tumour control (C6), vehicle control (V), naringenin (NGEN)-treated, drug-resistant tumour cells (C6R), and drug resistance cells added with NGEN (C6R+NGEN), to examine the impact of NGEN on migration and invasion. The effect of NGEN on filopodia length and density during cell migration was also studied in addition to the matrix metalloproteinases (MMP-2 and MMP-9) and p-ERK levels.

Results and Conclusion:

NGEN and C6R+NGEN groups had shown significant reduction (P < .01) in length and density of filopodia, colony formation, invasion and wound healing. Further, NGEN could also modify the assessed protein levels (P < .001), which were involved in migration and invasion in sensitive and resistant cells. Our study had provided the first evidence on NGEN-induced enhanced sensitivity against TMZ resistance with profound influence as an antimigratory and anti-invasive agent.

Methylation and expression patterns of tropomyosin-related kinase genes in different grades of glioma

Tropomyosin-related kinase family (NTRK1, NTRK2 and NTRK3) is well known to play an important role in the pathogenesis of brain tumour, which exhibit heterogeneity in its biological and clinical behaviour. However, the mechanism that regulates NTRKs in glioma is not well understood. The present study investigates the epigenetic status (methylation) of NTRKs and their expression in different grades of glioma. Promoter methylation and structural relationship of NTRKs was assessed using methylation-specific PCR followed by chromatin immunoprecipitation in brain tissue samples from 220 subjects with different grades of glioma. Control brain samples were also assessed similarly. Reverse transcriptase PCR was performed to analyse the expressions of NTRK mRNAs in the grades of glioma. In addition, the expression level of p75(NTR) protein was analysed using immunofluorescent technique in all of the samples. The overall percentage of NTRK3 gene methylation frequency with subsequent loss of mRNA expression was significantly higher in glioma compared with control samples (p < 0.05). No such significance was observed in other NTRK1 and NTRK2 genes. Further, mRNA expression pattern of NTRK1 and NTRK2 genes was found to be significantly higher in low grades as compared with high grades (HG) and control samples (p < 0.05). Survival rate of HG patients with negative expressions of NTRK1 and NTRK2 was poor than those with the positive expressions of both NTRK1 and NTRK2. Further, a significant correlation was observed with reduced expression of p75(NTR) and the expression pattern of NTRK family in glioma as compared with the control samples (p < 0.05). There exists a correlation between the expression of NTRK family and different grades of glioma with a significant suggestion that the promoter methylation does not play role in the regulation of these genes in glioma. Further, poor survival could be associated with NTRK mRNAs 1 and 2. Hence, NTRKs are potential probes for assessing the behaviour of different grades of glioma, which could also function as significant prognostic factors and thus deserve wider attention for an effective management of the grades.