Radon, smoking and HPV as lung cancer risk factors in ecological studies

Factors influencing temporal variations of radon concentration in high-rise buildings

Long-term radon time series were analyzed in 14 rooms and offices to search factors influencing indoor radon concentration in high-rise buildings. Radon entry to living rooms is determined both by diffusion from building materials and advection from adjoined low-ventilated spaces. Humans affect on seasonal and diurnal radon concentration changes in high-rise buildings by activating ventilation system. Indoor-outdoor temperature difference significantly influence on the air exchange rate under uncontrolled ventilation, which is especially important in new energy efficient buildings.

NEK2 plays an active role in Tumorigenesis and Tumor Microenvironment in Non-Small Cell Lung Cancer

Abnormal expression and dysfunction of Never-in-mitosis-A-related kinase 2 (NEK2) result in tumorigenesis. High levels of NEK2 are related to malignant progression, drug resistance, and poor prognosis. However, the relationship between NEK2 levels and the occurrence of non-small cell lung cancer (NSCLC) remains unknown. This study aimed to explore the impacts of NEK2 on the oncogenesis of NSCLC and the tumor microenvironment. Downregulation of NEK2 inhibited A549 and H1299 cell proliferation, migration, and invasion, blocking cell cycle at the G0/G1 phase. Loss of NEK2 inhibited the release of IL-10 from tumor cells, M2-like polarization of macrophages, angiogenesis, and vascular endothelial cell migration. Furthermore, NEK2 deficiency inhibited tumor growth in vivo. Taken together, NEK2 knockdown inhibited the occurrence and development of NSCLC, M2 polarization of macrophages, and angiogenesis. The abnormal expression of NEK2 might not only indicate tumor progression and patient prognosis but also serve as a potential molecular therapeutic target with great development prospects.

Circular RNA hsa_circ_0096157 contributes to cisplatin resistance by proliferation, cell cycle progression, and suppressing apoptosis of non-small-cell lung carcinoma cells

Circular RNAs (circRNAs) play a major role in cancer development and chemotherapy resistance. This study aimed to characterize circRNA profiles associated with Cisplatin (diamminedichloroplatinum, DDP) resistance of non-small-cell lung carcinoma (NSCLC) cells. The half-maximal inhibitory concentration (IC50) of A549 and A549/DDP cells was determined using CCK-8 assay. Further, circRNA profiles and differentially expressed genes in A549 and A549/DDP cells were characterized by deep sequencing and cell proliferation was measured using MTS assay. Cell cycle progression was analyzed using flow cytometry. Apoptosis experiment was performed by TUNEL assay and flow cytometry. Cell migration and invasion were assessed using the Transwell system. Finally, signalling protein levels related to cell cycle progression and migration were measured by western blot. CCK-8 assay showed that A549/DDP cells obtained strong DDP resistance. Further deep sequencing results showed that 689 circRNAs and 87 circRNAs were significantly upregulated and downregulated in A549/DDP cells compared to A549 cells, respectively. Moreover, the circRNA hsa_circ_0096157 with the highest expression level in A549/DPP cells was further analyzed for its potential mechanism of DDP resistance in A549/DDP. With or without DDP treatment, hsa_circ_0096157 knockdown inhibited proliferation, migration, invasion and cell cycle progression but promoted apoptosis of A549/DDP cells. In addition, the western blot results also showed that hsa_circ_0096157 knockdown in A549/DDP cells increased P21 and E-cadherin but decreased CDK4, Cyclin D1, Bcl-2, N-cadherin, and Vimentin protein expression levels, indicating that cell cycle progression might be inhibited by increased P21 protein level to inhibit the expression of CDK4-cyclin D1 complex and decreased Bcl-2 protein level; and migration and invasion were suppressed by the increased E-cadherin and decreased N-cadherin and Vimentin expression levels. In contrast, hsa_circ_0096157 overexpression in A549 cells caused the opposite cellular and molecular alterations. DDP resistance in NSCLC cells was associated with significant circRNA profile alterations. Moreover, increased hsa_circ_0096157 expression contributed to DDP resistance in NSCLC cells by promoting cell proliferation, migration, invasion and cell cycle progression and inhibiting apoptosis.

Expression of p16 and p53 in non-small-cell lung cancer: clinicopathological correlation and potential prognostic impact

Aim: p16 and p53 are frequently altered intracellular pathways in cancers. We investigated the aberrant expression of p16 and its relationship with p53 and HPV status in primary non-small-cell lung carcinoma. Patients & methods: Lung tumor tissue microarray (n = 163), immunohistochemical study of p16 and p53, and HPV in-situ hybridization were analyzed. Results: p16 and p53 were detected in 50.7 and 57.3% of adenocarcinoma (ADCs; n = 75), and 35.2 and 63.6% of squamous cell carcinoma (n = 88). HPV was detected in 16 and 10.2% of ADC and squamous cell carcinoma. In ADCs, p16 positive tumors demonstrated a favorable median overall survival time of 60.9 months, compared with p16 negative tumors of 46.9 months (p < 0.05). Furthermore, we did not find significant relationships between p16 expression and HPV status, nor with p53 expression. Conclusion: p16 play an unique role in lung cancer survival. The mechanism of p16 needs to be further studied.

Meta-analysis of case-control studies on the relationship between lung cancer and indoor radon exposure

Indoor exposure to natural radon is a factor that influences lung cancer risk worldwide. The present study includes a meta-analysis of epidemiological data on the relationship between lung cancer and indoor radon. Altogether, 31 case-control studies with 20,703 cases, 34,518 controls and 140 individual odds ratio (OR) estimates are included in the meta-analysis. Weighted median OR was calculated for five radon intervals. The following parameters were used for the weighting: standard error of OR, duration of radon concentration measurement, and relative number of controls in reference intervals. The dependence of the weighted median OR on the radon concentration was estimated applying linear non-threshold and threshold models. The results obtained suggest a significant linear no-threshold exposure-effect relationship for radon concentrations above 100 Bq/m³, with a slope of 0.14 (95% confidence interval 0.08-0.21) per 100 Bq/m³.