N6-methyladenosine upregulates ribosome biogenesis in environmental carcinogenesis.

Many trace metal pollutants in surface water, the atmosphere, and soil are carcinogenic, and ribosome biogenesis plays an important role in the carcinogenicity of heavy metals. However, the contradiction between upregulated ribosome biogenesis and decreased ribosomal DNA copy number in environmental carcinogenesis is not fully understood. Here, from a perspective of the most predominant and abundant RNA epigenetic modification, N6-methyladenosine (m6A), we explored the reason behind this contradiction at the post-transcriptional level using arsenite-induced skin carcinogenesis models both in vitro and in vivo. Based on the m6A microarray assay and a series of experiments, we found for the first time that the elevated m6A in arsenite-induced transformation is mainly enriched in the genes regulating ribosome biogenesis. m6A upregulates ribosome biogenesis post-transcriptionally by stabilizing ribosomal proteins and modulating non-coding RNAs targeting ribosomal RNAs and proteins, leading to arsenite-induced skin carcinogenesis. Using multi-omics analysis of human subjects and experimental validation, we identified an unconventional role of a well-known key proliferative signaling node AKT1 as a vital mediator between m6A and ribosome biogenesis in arsenic carcinogenesis. m6A activates AKT1 and transmits proliferative signals to ribosome biogenesis, exacerbating the upregulation of ribosome biogenesis in arsenite-transformed keratinocytes. Similarly, m6A promotes cell proliferation by upregulating ribosome biogenesis in cell transformation induced by carcinogenic heavy metals (chromium and nickel). Importantly, inhibiting m6A reduces ribosome biogenesis. Targeted inhibition of m6A-upregulated ribosome biogenesis effectively prevents cell transformation induced by trace metals (arsenic, chromium, and nickel). Our results reveal the mechanism of ribosome biogenesis upregulated by m6A in the carcinogenesis of trace metal pollutants. From the perspective of RNA epigenetics, our study improves our understanding of the contradiction between upregulated ribosome biogenesis and decreased ribosomal DNA copy number in the carcinogenesis of environmental carcinogens.

Efficacy of ginseng oral administration and ginseng injections on cancer-related fatigue: A meta-analysis.

BACKGROUND: Up to 90% of patients who are under the active treatment suffer from cancer-related fatigue (CRF). CRF can persist about 10 years after diagnosis and/or treatment. Accumulating reports support that ginseng and ginseng injections are both potential drugs for the treatment of CRF but few studies put them together for analysis. METHODS: Two reviewers independently extracted data in 3 databases (PubMed, Cochrane Library and China National Knowledge Infrastructure) from their inception to May 24, 2021. The primary outcome was the effect of ginseng in alleviating CRF. The secondary outcome was ginseng in alleviating emotional or cognitive fatigue. Standardized mean difference (SMD) was employed. RESULTS: Twelve studies were included to evaluate efficacy of ginseng oral administration and ginseng injections on CRF. The pooled SMD was 0.40 (95% confidence Interval [95% CI] [0.29-0.51], P < .00001). Six studies were included to evaluate efficacy of ginseng oral administration on CRF and the SMD was 0.29 (95% CI [0.15-0.42], P < .0001). The order was 2000 mg/d, 3000 mg/d, 1000 mg/d and placebo from high efficacy to low. Ten studies were included to evaluate efficacy of ginseng injections on CRF and the SMD was 0.74 (95% CI [0.59-0.90], P < .00001). Emotional fatigue was reported in 4 studies, ginseng oral administration in 2 and ginseng injections in 2. The pooled SMD was 0.12 (95% CI [-0.04 to 0.29], P = .15). Cognitive fatigue was reported in 4 studies focusing on ginseng injections and the SMD was 0.72 (95% CI [0.48-0.96], P < .00001). CONCLUSION: Ginseng can improve CRF. Intravenous injection might be better than oral administration. Ginseng injections may alleviate cognitive fatigue. No evidence was found to support that ginseng could alleviate emotional fatigue.