p53 Activates the Long Noncoding RNA Pvt1b to Inhibit Myc and Suppress Tumorigenesis.

The tumor suppressor p53 transcriptionally activates target genes to suppress cellular proliferation during stress. p53 has also been implicated in the repression of the proto-oncogene Myc, but the mechanism has remained unclear. Here, we identify Pvt1b, a p53-dependent isoform of the long noncoding RNA (lncRNA) Pvt1, expressed 50 kb downstream of Myc, which becomes induced by DNA damage or oncogenic signaling and accumulates near its site of transcription. We show that production of the Pvt1b RNA is necessary and sufficient to suppress Myc transcription in cis without altering the chromatin organization of the locus. Inhibition of Pvt1b increases Myc levels and transcriptional activity and promotes cellular proliferation. Furthermore, Pvt1b loss accelerates tumor growth, but not tumor progression, in an autochthonous mouse model of lung cancer. These findings demonstrate that Pvt1b acts at the intersection of the p53 and Myc transcriptional networks to reinforce the anti-proliferative activities of p53.

5-Fluorouracil efficacy requires anti-tumor immunity triggered by cancer-cell-intrinsic STING.

5-Fluorouracil (5-FU) is a widely used chemotherapeutic drug, but the mechanisms underlying 5-FU efficacy in immunocompetent hosts in vivo remain largely elusive. Through modeling 5-FU response of murine colon and melanoma tumors, we report that effective reduction of tumor burden by 5-FU is dependent on anti-tumor immunity triggered by the activation of cancer-cell-intrinsic STING. While the loss of STING does not induce 5-FU resistance in vitro, effective 5-FU responsiveness in vivo requires cancer-cell-intrinsic cGAS, STING, and subsequent type I interferon (IFN) production, as well as IFN-sensing by bone-marrow-derived cells. In the absence of cancer-cell-intrinsic STING, a much higher dose of 5-FU is needed to reduce tumor burden. 5-FU treatment leads to increased intratumoral T cells, and T-cell depletion significantly reduces the efficacy of 5-FU in vivo. In human colorectal specimens, higher STING expression is associated with better survival and responsiveness to chemotherapy. Our results support a model in which 5-FU triggers cancer-cell-initiated anti-tumor immunity to reduce tumor burden, and our findings could be harnessed to improve therapeutic effectiveness and toxicity for colon and other cancers.

The global burden of heterogeneity of lupus erythematosus interventional trials.

To explore bias in lupus erythematosus (LE) randomized clinical trials (RCTs) and to help the development of benchmarks for future trials and management. We searched systematically three databases and three registries to summarize the interventional randomized clinical trials (RCTs) and identify factors associated with participant loss. Trials which examined pharmacological interventions with control group were included and a meta-analysis was carried out by using fixed and random effects models to calculate risk ratio of participant loss in the intervention and control groups. A total of 481 trials with 68,582 participants met our inclusion criteria, organ specific interventional studies along with trials that address quality of life attributes and geopolitical disparities are missing or lagging behind. 90 trials were involved in the meta-analyses, the withdrawal ratio between intervention and control groups was distinctly influenced by national income of the trial-conducted country. In high income countries, the withdrawal ratio was relatively constant, while for trials conducted in low and middle income countries, the results were altered by trial registration, year of start, number of centers, number of participants, and primary outcome identification. Moreover, the comparability of participants was also worrying, trial location and registration status altered basal participant adherence. Our study reveals the unexpectedly huge heterogeneity brought by national income and trial registration in lupus RCTs worldwide. To maintain the fundamental repeatability and referenceability of LE RCTs, rigorously designed single-country trials with diverse inclusion criteria are needed.

The Systemic Lupus Erythematosus Interventional Trials in Mainland China: A Continuous Challenge.

Objectives: More than a quarter of single-country systemic lupus erythematosus (SLE) interventional randomized clinical trials (RCTs) were conducted in China. To help develop management guidelines and set benchmarks for future SLE research, a systematic review of current trials is needed. Methods: We searched systematically three databases and four registries to summarize the interventional RCTs in mainland China and identify factors associated with participant loss. The internal validity of trials was assessed using the Cochrane risk-of-bias tool for assessing risk of bias. The odds ratio (OR) was defined as the ratio of the odds of less than 10% loss to follow-up in the presence or absence of different factors. Results: A total of 188 trials met our inclusion criteria, and 15·5% of trials conducted in mainland China ranked low risk of bias. Participant loss was significantly higher among trials that had a defined primary outcome or were registered {primary outcome identification (0·02 [0·00-0·23]) and registration (0·14 [0·03-0·69])}. Trials examining traditional Chinese medicine (TCM) pharmacological treatments had an 8·16-fold (8·16 [1·28-51·98]) higher probability of having low participant loss than trials examining non-TCM pharmacological treatment trials, and trials that did not report masking status had a 15·95-fold (15·95 [2·45-103·88]) higher probability of having low participant loss than open-label trials. In addition, published articles in Chinese also had higher probability of having low participant loss (5·39 [1·10-26·37]). Conclusion: SLE trials conducted in mainland China were of relatively poor quality. This situation, including nonrigorous design, lack of registration, and absence of compliance reporting, needs to be ameliorated. To maintain the fundamental repeatability and comparability of mainland China SLE RCTs, transparency of the clinical trial process and complete reporting of the trial data are crucial and urgently needed.