Lung tissue regeneration after induced injury in Runx3 KO mice

Recent advances in dead cell clearance during acute lung injury and repair

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are clinical syndromes that cause significant mortality in clinical settings and morbidity among survivors accompanied by huge healthcare costs. Lung-resident cell dysfunction/death and neutrophil alveolitis accompanied by proteinous edema are the main pathological features of ALI/ARDS. While understanding of the mechanisms underlying ALI/ARDS pathogenesis is progressing and potential treatments such as statin therapy, nutritional strategies, and mesenchymal cell therapy are emerging, poor clinical outcomes in ALI/ARDS patients persist. Thus, a better understanding of lung-resident cell death and neutrophil alveolitis and their mitigation and clearance mechanisms may provide new therapeutic strategies to accelerate lung repair and improve outcomes in critically ill patients. Macrophages are required for normal tissue development and homeostasis as well as regulating tissue injury and repair through modulation of inflammation and other cellular processes. While macrophages mediate various functions, here we review recent dead cell clearance (efferocytosis) mechanisms mediated by these immune cells for maintaining tissue homeostasis after infectious and non-infectious lung injury.

Association between RUNX3 promoter methylation and non-small cell lung cancer: a meta-analysis

BACKGROUND

Runt-related transcription factor 3 (RUNX3) is a known regulator in the transforming growth factor (TGF)-β signaling pathway, which promoter methylation playing a crucial role in diverse neoplasias. However, the relationship between RUNX3 promoter methylation and non-small cell lung cancer (NSCLC) remains to be clarified.

METHODS

We searched Pubmed, Embase, Cochrane Central, and Chinese Biological Medicine database, for articles published in English or Chinese until March 7, 2014. Our main analyses were focused on the association between RUNX3 promoter methylation and risk of NSCLC by meta-analysis methods. If heterogeneity was observed, we used random effects model to calculate the overall odds ratios, otherwise fixed effects model was used. Subgroup analyses and meta-regression analyses were employed to detect the sources of the heterogeneity. Sensitivity analysis was performed to evaluate the stability of our studies. A funnel plot and Egger's test were conducted to investigate any potential publication bias.

RESULTS

A total of 1,368 samples from 13 literatures were involved in this meta-analysis. The pooled odds ratio (OR) of RUNX3 methylation in NSCLC specimens compared to non-cancer controls was 6.70 [95% confidence interval (CI): 4.64-9.67]. In the analysis of specimen-types subgroup, the summary OR was 5.79 (95% CI: 3.97-8.46) for tissue specimen subgroup, and that was 45.64 (95% CI: 5.89-353.72) for serum specimen subgroup. The ORs for the age ≤60 years, 60-65 years and >65 years subgroup were 5.19 (95% CI: 3.27-8.24), 9.45 (95% CI: 2.45-36.45) and 13.23 (95% CI: 5.59-31.28) respectively. The result of meta-regression indicated that age was fundamental source of heterogeneity (coefficient =0.61, P=0.046, adjusted R(2) =100%). No publication bias was detected. In cancer specimens, the RUNX3 methylation was associated with histological type of the NSCLC, but no significant differences were found for RUNX3 methylation in relation to gender, smoking history, tumor TNM stage or tumor differentiation level.

CONCLUSIONS

This meta-analysis of pooled data provides additional evidence to support a strong association between methylation of the RUNX3 promoter and NSCLC. RUNX3 methylation was increasing with age.

Effects of paeonol on intracellular calcium concentration and expression of RUNX3 in LoVo human colon cancer cells

Paeonol, a major phenolic component of the root bark of Paeonia moutan, is known to exhibit antitumor effects. However, the underlying mechanisms remain unknown. In the present study, the effects of paeonol on cell viability, intracellular calcium concentration and the expression of runt‑related transcription factor 3 (RUNX3) were analyzed in LoVo human colon cancer cells. Results revealed that paeonol markedly reduced LoVo cell viability in a time‑ and dose‑dependent manner. Flow cytometry assays demonstrated that paeonol blocked the cell cycle at the G1 to S transition and significantly induced apoptosis in LoVo cells. Intracellular calcium accumulation occurred following a 48 h treatment with paeonol. Furthermore, RUNX3 gene expression was increased in paeonol‑treated cells. These observations indicate that paeonol possesses antiproliferative properties and apoptosis‑inducing activity. One of the antitumor mechanisms of paeonol may be its apoptosis‑inducing activity through an increased intracellular calcium concentration and the upregulation of RUNX3 expression. Paeonol may be a promising antitumor agent for colon carcinoma treatment.

RUNX3 downregulation in human lung adenocarcinoma is independent of p53, EGFR or KRAS status

RUNX3 aberrations play a pivotal role in the oncogenesis of breast, gastric, colon, skin and lung tissues. The aim of this study was to characterize further the expression of RUNX3 in lung cancers. To achieve this, a lung cancer tissue microarray (TMA), frozen lung cancer tissues and lung cell lines were examined for RUNX3 expression by immunohistochemistry, while the TMA was also examined for EGFR and p53 expression. RUNX3 promoter methylation status, and EGFR and KRAS mutation status were also investigated. Inactivation of RUNX3 was observed in 70% of the adenocarcinoma samples, and this was associated with promoter hypermethylation but not biased to EGFR/KRAS mutations. Our results suggest a central role of RUNX3 downregulation in pulmonary adenocarcinoma, which may not be dependent of other established cancer-causing pathways and may have important diagnostic and screening implications.