The epigenetics orchestra of Notch signaling: a symphony for cancer therapy

The aberrant regulation of the Notch signaling pathway, which is a fundamental developmental pathway, has been implicated in a wide range of human cancers. The Notch pathway can be activated by both canonical and noncanonical Notch ligands, and its role can switch between acting as an oncogene or a tumor suppressor depending on the context. Epigenetic modifications have the potential to modulate Notch and its ligands, thereby influencing Notch signal transduction. Consequently, the utilization of epigenetic regulatory mechanisms may present novel therapeutic opportunities for both single and combined therapeutics targeted at the Notch signaling pathway. This review offers insights into the mechanisms governing the regulation of Notch signaling and explores their therapeutic potential.

Insights into the Links between MYC and 3D Chromatin Structure and Epigenetics Regulation: Implications for Cancer Therapy

MYC is embedded in the transcriptional oasis of the 8q24 gene desert. A plethora of genomic elements has roles in MYC aberrant expression in cancer development by interacting with transcription factors and epigenetics regulators as well as altering the structure of chromatin at the MYC locus and tissue-specific long-range enhancer-promoter contacts. Furthermore, MYC is a master regulator of several human cancers by modulating the transcription of numerous cancer-related genes through epigenetic mechanisms. This review provides a comprehensive overview of the three-dimensional genomic organization around MYC and the role of epigenetic machinery in transcription and function of MYC as well as discusses various epigenetic-targeted therapeutic strategies in MYC-driven cancers.

Wnt signaling pathway in osteoporosis: Epigenetic regulation, interaction with other signaling pathways, and therapeutic promises

Wnt is a major signaling pathway involved in multifaceted roles of various biological processes. Bones are dynamic tissues which are able to remodel and maintain the tissue homeostasis. Wnt signaling cascade leads to the promotion of bone formation and suppression of bone resorption, leading to a balance in bone remodeling. Recent evidence has reinforced the inevitable role of Wnt signaling in osteoporosis. The complex genetic and epigenetic regulations of Wnt signaling factors and their interaction with other master signaling pathways such as TGF-β, BMP, PI3K/AKT, and Hedgehog outline their importance in diagnosis and treatment of osteoporosis. In this review, we highlighted the recent advances in function of Wnt signaling-related epigenetic regulation, different signaling pathways interacting with Wnt, and their roles in osteoporosis. Finally, we discussed novel promises in molecular targeted therapy of osteoporosis.

Informative combination of CLU rs11136000, serum HDL levels, diabetes, and age as a new piece of puzzle-picture of predictive medicine for cognitive disorders

Clusterin (CLU) is the third most important associated risk gene in cognitive disorders. Regarding the controversy about the association of CLU rs11136000 with mild cognitive impairment (MCI), the aim of this study was to investigate a putative association of CLU rs11136000 with MCI as well as the serum biological factors with a special attention to the age as a main dimension of a multifactorial elderly disease in an Iranian elderly cohort in which the mentioned association was not previously investigated. The study also checked the association between diabetes and MCI in this population. A population of 418 individuals containing 236 MCI and 192 control subjects was recruited from the Amirkola health and aging population cohort. Serum biological indexes were assessed by biochemical and enzyme-linked immunosorbent assay, and rs11136000 genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism. Bioinformatics analyses were used to identify the putative effect of rs11136000 on the secondary structure of RNA and chromatin location in different cell lines and tissues. Type 2 diabetes was present with a higher proportion in the MCI group in comparison with the control group (P = 0.041). The frequency of the C allele of CLU rs11136000 was significantly different between cases and controls and was associated with MCI risk (OR 1.79, P = 0.019). Under a dominant genetic model, the CC genotype showed a predisposing effect in individuals aged ≥ 75 years (OR 3.33, P = 0.0004). Interestingly, under an over-dominant model, the CT genotype had a protective effect in this population (OR 4.52, P = < 0.0001). We also found a significant association between the genotypes and high-density lipoprotein (HDL) levels in MCI patients (P = 0.0004). Bioinformatics analysis showed that rs11136000 is located in the transcribed region without any regulatory features such as being enhancer or insulator. Also, the T>C transition of CLU rs11136000 could not cause significant mRNA folding (P = 0.950). Contrary to other studies on Asian populations, this study demonstrated an association between rs11136000 and MCI in an elderly Iranian population. This study also suggests that an age-dependent approach to the previous studies may be performed in order to revise the previous belief in this geographical area. The rs11136000 genotypes in combination with HDL levels and knowledge about diabetes background may be used as a predictive medicine tool for cognitive disorders.

DNA methyltransferases and gastric cancer: insight into targeted therapy

Gastric cancer is a major health problem worldwide occupying most frequent causes of cancer-related mortality. In addition to genetic modifications, epigenetic alterations catalyzed by DNA methyltransferases (DNMTs) are a well-characterized epigenetic hallmark in gastric cancer. The reversible nature of epigenetic alterations and central role of DNA methylation in diverse biological processes provides an opportunity for using DNMT inhibitors to enhance the efficacy of chemotherapeutics. In this review, we discussed key factors or mechanisms such as SNPs, infections and genetic modifications that trigger DNMTs level modification in gastric cancer, and their potential roles in cancer progression. Finally, we focused on how inhibitors of the DNMTs can most effectively be used for the treatment of gastric cancer with multidrug resistance.

Association of interleukin-6 (rs1800796) but not transforming growth factor beta 1 (rs1800469) with serum calcium levels in osteoporotic patients

BACKGROUND

Osteoporosis is a multifactorial disease with a strong genetic influence. Recent studies have demonstrated that cytokines, such as TGF-β1 and interleukin 6 (IL-6) play complex roles in the normal bone metabolism and pathophysiology of osteoporosis. Here, we investigated the roles of 2 polymorphisms mapping to the promoters of TGF-β1and IL-6 genes on the genetic susceptibility to osteoporosis as well as calcium and vitamin D levels.

METHODS

A cohort of 297 elderly participants in northern Iran comprising 181 osteoporotic patients (mean age ± SD, 68.36 ± 7.21 years) and 116 unrelated healthy controls (mean age ± SD, 64 ± 5.44 years) was studied for TGF-β1(C-509T) and IL-6 (G-634C) polymorphisms using PCR-RFLP method.

RESULTS

A significant relationship was observed between calcium level and IL-6 genotypes in osteoporotic males (P = 0.011) and females (P = 0.020). No significant differences were observed between osteoporotic and control groups with respect to allele frequency or genotype distribution based on the 2 selected polymorphisms under different genetic models. The results remained the same after comparing the BMD values of either the femur neck or lumbar spine with the genotypes of the elderly men and women when analyzed separately.

CONCLUSION

IL-6 genotype influences serum calcium levels in osteoporotic patients. The lack of association between the common genetic variations of TGF-β1 and IL-6 genes, and BMD highlights the complex genetic background of osteoporosis in the north of Iran.