DNA Methylation of thehTERTGene in Breast Cancer Revisited: Diagnostic and Clinical Implications

Impact of Stilbenes as Epigenetic Modulators of Breast Cancer Risk and Associated Biomarkers

With the recent advancement of genetic screening for testing susceptibility to mammary oncogenesis in women, the relevance of the gene−environment interaction has become progressively apparent in the context of aberrant gene expressions. Fetal exposure to external stressors, hormones, and nutrients, along with the inherited genome, impact its traits, including cancer susceptibility. Currently, there is increasing interest in the role of epigenetic biomarkers such as genomic methylation signatures, plasma microRNAs, and alterations in cell-signaling pathways in the diagnosis and primary prevention of breast cancer, as well as its prognosis. Polyphenols like natural stilbenes have been shown to be effective in chemoprevention by exerting cytotoxic effects that can stall cell proliferation. Besides possessing antioxidant properties against the DNA-damaging effects of reactive oxygen species, stilbenes have also been observed to modulate cell-signaling pathways. With the increasing trend of early-life screening for hereditary breast cancer risks, the potency of different phytochemicals in harnessing the epigenetic biomarkers of breast cancer risk demand more investigation. This review will explore means of exploiting the abilities of stilbenes in altering the underlying factors that influence breast cancer risk, as well as the appearance of associated biomarkers.

Epigenetic and breast cancer therapy: Promising diagnostic and therapeutic applications

The global burden of breast cancer (BC) is increasing significantly. This trend is caused by several factors such as late diagnosis, limited treatment options for certain BC subtypes, drug resistance which all lead to poor clinical outcomes. Recent research has reported the role of epigenetic alterations in the mechanism of BC pathogenesis and its hallmarks include drug resistance and stemness features. The understanding of these modifications and their significance in the management of BC carcinogenesis is challenging and requires further attention. Nevertheless, it promises to provide novel insight needed for utilizing these alterations as potential diagnostic, prognostic markers, predict treatment efficacy, as well as therapeutic agents. This highlights the importance of continuing research development to further advance the existing knowledge on epigenetics and BC carcinogenesis to overcome the current challenges. Hence, this review aims to shed light and discuss the current state of epigenetics research in the diagnosis and management of BC.

Aberrant hTERT promoter methylation predicts prognosis in Chinese patients with acral and mucosal melanoma: A CONSORT-compliant article

BACKGROUND

To evaluate the methylation levels of human telomerase reverse transcriptase (hTERT) promoter three CpG island (CGIs) regions and its prognostic impact in Chinese patients with acral and mucosal melanoma.

METHODS

Bioinformatics software was used to analyze hTERT gene promoter. Fresh frozen tissues were taken from 14 patients with melanoma (6 acral melanoma and 8 mucosal melanoma) and 14 pigmented nevus as control subjects (14 acral pigmented nevus). Bisulfite sequencing PCR (BSP) combined TA clone sequencing was used to assess the methylation levels of hTERT promoter CGIs regions. The relative expression level of hTERT mRNA was measured by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

CGIs-1 (-1392--1098 bp), CGIs-2 (-945--669 bp), and CGIs-3 (-445--48 bp) were selected for our study. Our results indicated that the methylation levels of hTERT promotor CGIs regions in melanoma were greater than pigmented nevus (CGIs-1: 69.3 ± 18.7% vs 46.8 ± 20.4%, t = 3.048 P = .005; CGIs-2: 73.8 ± 14.7% vs 55.6 ± 16.0%, t = 3.120 P = .004; CGIs-3: 5.8 ± 2.2% vs 2.2 ± 1.3%, t = 5.164 P < .001). The relative expression level of hTERT in melanoma was greater than in pigmented nevus (50.39 ± 9.16 vs 26.10 ± 7.25, t = 7.778, P < .001). Linear regression analysis showed that the methylation level of CGIs-2 in melanoma was positively correlated with the relative expression level of hTERT mRNA (R = .490, F = 13.478, P = .003). Combined with the analysis of clinicopathological features, the methylation level of CGIs-2 in melanoma with lymph node metastasis was greater than in melanoma without lymph node metastasis, and the methylation level of CGIs-2 increased with TNM staging.

CONCLUSION

CGIs-2 methylation level was associated with the relative expression level of hTERT mRNA, lymph node metastasis and TNM staging, suggesting that CGIs-2 hypermethylation might be used to evaluate the prognosis in Chinese patients with acral and mucosal melanoma.