Non-coding RNAs' function in cancer development, diagnosis and therapy

While previous research on cancer biology has focused on genes that code for proteins, in recent years it has been discovered that non-coding RNAs (ncRNAs)play key regulatory roles in cell biological functions. NcRNAs account for more than 95% of human transcripts and are an important entry point for the study of the mechanism of cancer development. An increasing number of studies have demonstrated that ncRNAs can act as tumor suppressor genes or oncogenes to regulate tumor development at the epigenetic level, transcriptional level, as well as post-transcriptional level. Because of the importance of ncRNAs in cancer, most clinical trials have focused on ncRNAs to explore whether ncRNAs can be used as new biomarkers or therapies. In this review, we focus on recent studies of ncRNAs including microRNAs (miRNAs), long ncRNAs (lncRNAs), circle RNAs (circRNAs), PIWI interacting RNAs (piRNAs), and tRNA in different types of cancer and explore the application of these ncRNAs in the development of cancer and the identification of relevant therapeutic targets and tumor biomarkers. Graphical abstract drawn by Fidraw.

Gastric cancer stem cell-derived exosomes promoted tobacco smoke-triggered development of gastric cancer by inducing the expression of circ670

As one of the most common malignant cancers in the world, gastric cancer is caused by mang factors among which tobacco smoke is an important risk factor. Gastric cancer stem cells (GCSCs) and the derived exosomes play a key role in the occurrence and development of gastric cancer, and exosomal circRNA is considered as a new regulatory factor in the development of gastric cancer. However, it is unclear whether tobacco smoke can affect exosomes and their transport circRNAs to promote the development of gastric cancer. Herein, we provided a new insight into tobacco smoke promoting the progression of gastric cancer. In the present study, we demonstrated that tobacco smoke-induced exosomes promoted the spheroidizing ability, stemness genes expression, and epithelial-mesenchymal transition (EMT) process of GCSCs. We further found that hsa-circRNA-000670 (circ670) was up-regulated in tissues of gastric cancer patients with smoking history, tobacco smoke-induced GCSCs, and their exosomes. Functional assays have shown that circ670 knockdown inhibited the stemness and EMT process of GCSCs, whereas circ670 overexpression appeared to have an opposite effect. Our findings indicated that exosomal circ670 promotes the development of tobacco smoke-induced gastric cancer, which may provide insight into the mechanism of tobacco smoke promoting the progression of gastric cancer.

Role of ferroptosis and ferroptosis-related non-coding RNAs in the occurrence and development of gastric cancer

Gastric cancer (GC) is a malignant cancer of the digestive tract and is a life-threatening disease worldwide. Ferroptosis is a newly discovered form of regulated cell death, which involves the accumulation of iron-dependent lipid peroxides. It has been found that ferroptosis plays an important regulatory role in the occurrence, development, drug resistance, and prognosis of GC. Non-coding RNAs (ncRNAs) play a critical role in the occurrence and progression of a variety of diseases including GC. In recent years, the role of ferroptosis and ferroptosis-related ncRNAs (miRNA, lncRNA, and circRNA) in the occurrence, development, drug resistance, and prognosis of GC has attracted more and more attention. Herein, we briefly summarize the roles and functions of ferroptosis and ferroptosis-related ncRNAs in GC tumorigenesis, development, and prognosis. We also prospected the future research direction and challenges of ferroptosis and ferroptosis-related ncRNAs in GC.

Circular RNA and Its Roles in the Occurrence, Development, Diagnosis of Cancer

Circular RNAs (circRNAs) are non-coding single-stranded covalently closed circular RNA, mainly produced by reverse splicing of exons of precursor mRNAs (pre-mRNAs). The characteristics of high abundance, strong specificity, and good stability of circRNAs have been discovered. A large number of studies have reported its various functions and mechanisms in biological events, such as the occurrence and development of cancer. In this review, we focus on the classification, characterization, biogenesis, functions of circRNAs, and the latest advances in cancer research. The development of circRNAs as biomarkers in cancer diagnosis and treatment also provides new ideas for studying circRNAs research.

Tobacco Smoke Plays an Important Role in Initiation and Development of Lung Cancer by Promoting the Characteristics of Cancer Stem Cells

Lung cancer is one of the most common causes of cancer-related deaths worldwide. Tobacco smoke is the single greatest risk factor of lung cancer. Although enormous progress in understanding the molecular mechanisms by which tobacco smoke leading to lung cancer has been made, the molecular pathogenesis remains largely unclear. Cancer stem cells have been implicated in cancer initiation, development, and drug resistance. In this review, we reviewed the relationship between tobacco smoke and lung cancer, the key role of cancer stem cells in lung cancer and other tumors. More importantly, we elucidate the mechanism of tobacco smoke promoting lung cancer from the perspective of the characteristics of cancer stem cells induced by tobacco smoke.

Charge inhomogeneity of carbon

Charge distribution on every atom of carbon matter in four dimension forms (cluster, fullerene, atomistic carbon chain, nanotube, graphene, surface and solid) was investigated by the first-principles calculation. It is found that the charge distribution in most of these materials is inhomogeneous, even in one certain solid phase. We found that if one atom in carbon has different surrounding environment from another one nearby, they always have electron transfer, that is, they have different charge. In round C₁₀ ring, C₂₄ and C₆₀ fullerenes, charge is zero, while charge is not zero in pentagon C₁₀ ring, C₃₀ and C₇₀ fullerenes. At the ends of atomistic chains, nanotube or on the edges of graphenes, carbon atoms have larger positive or negative charge, while almost zero in the central parts. Charge is zero in diamond and graphite, while it is not zero in the high pressure solid phase hexagonite or on some carbon surfaces. The non-zero charge in carbon possibly means its non-zero valence.

Simulation of the distribution of main atmospheric pollutants and the influence of land use on them in central urban area of Nanchang City, China

With the rapid urbanization and industrialization in China, atmospheric pollution becomes increasingly urgent. It is of great importance to examine the distribution of atmospheric pollutants and the influence of land use for sake of reducing pollution. We simulated and analyzed the temporal and spatial distribution characteristics of the six main atmospheric pollutants in the central urban area of Nanchang City, i.e. PM_2.5, PM₁₀, SO₂, NO₂, CO and O₃ based on land-use regression models (LUR). Four types of area, i.e. residential, commercial, educational and industrial area, were defined according to dominated land use type. Fifteen samples from each type were collected. The concentration of six air pollutants of fifteen sample areas for each type and each season were averaged to reduce the influence of meteorological factors. By means of double factor varian-ce analysis and multiple comparisons, we analyzed the effects of land use (expressed by sample area) on those atmospheric pollutants. The results showed that the concentrations of all the six atmospheric pollutants were well simulated by LUR model, with an average absolute error were 11.9%, 13.4%, 12.5%, 12.0%, 12.7% and 13.5% respectively. The concentration of six atmospheric pollutants showed obvious temporal and spatial distribution characteristics, with O₃ presenting the highest in summer, then spring, autumn, and winter in order, and the remaining five pollutants peaked in winter, then spring, autumn and summer in order. The concentrations of PM_2.5, PM₁₀, SO₂, NO₂ and CO showed a decreasing trend from urban center to suburb, while the concentration of O₃ was the opposite. The concentrations of varied seasons or land use sample areas were all significantly different, indicating that both meteorology and land use had significant effects on air pollution. The effects of land use on main atmospheric pollutants varied, with stronger effects on PM_2.5, NO₂ and O₃ than on CO.

[Influence of land intensive use level on main atmospheric pollutants in the central urban area of Nanchang City, China.]

At present, urbanization has gradually changed from denotative expansion to connotative development in China. It is urgently needed for intensive use of land resources and the construction of "compact city". However, intensive land use means less land resources to carry more urban elements, therefore people will become more and more sensitive to environmental pollution, especially atmospheric pollution. It is of great significance to study the influence of intensive land use on atmospheric pollution. Taking the central urban area of Nanchang City as a case, this study simulated the concentration of the six main atmospheric pollutants i.e. PM_2.5, PM₁₀, SO₂, NO₂, CO and O₃ by ordinary kriging interpolation firstly. Then, sixteen intensive land use variables, including the volume ratio, building density, population density, were analyzed with the partial least squares regression and path analysis in order to reveal the effects of intensive land use level on the atmospheric pollutants. The results showed that the correlations between intensive land use level and PM_2.5, PM₁₀ were the strongest, followed by O₃ and NO₂, and the weakest correlation was between intensive land use level and SO₂, CO. The sequence of the correlation between intensive land use variables and the six main atmospheric pollutants in different sample areas was residential area> education area > business area > industrial area. The more intensive the land use was, it had greater impacts on the atmospheric pollutants. The greatest effect was on PM_2.5 and PM₁₀, followed by O₃, and the least effect was on NO₂. The direct, indirect, and integrated influences of intensive land use on atmospheric pollutants were generally equal. Overall, the direct influence of the intensive land use level was greater than the indirect one, among which the influence of the intensive land use level of the residential area was the strongest, followed by the business area, and the education area least. This study provided a new perspective on studying the influence of intensive land use on atmospheric environment, which would provide some reference to solve the atmospheric problems in compacted city.

Regulation of NK92-MI cell cytotoxicity by substance P

The neuropeptide substance P (SP) can regulate a number of immunological functions in vitro and in vivo and may regulate natural killer (NK) cell activity. Here, we investigated whether SP has a role in regulating NK92-MI cell function in vitro, and how it influences NK cell activity. We found that SP dose dependently increased the cytotoxicity of NK92-MI cells and had a maximal effect at a concentration of 10(-12) and 10(-10) m. Furthermore, the expression of cytotoxic-associated molecules (perforin, granzyme) and activating receptor NKp46 [a member of natural cytotoxicity receptors (NCRs)] was observed to be upregulated by SP at optimal concentration, at which SP enhanced the cytotoxicity of NK92-MI cells. Neurokinin-1 receptor (NK-1R), a functional receptor of SP, was found on NK92-MI cells, and the observed effects of SP on NK92-MI cells could be more partially blocked by an NK-1R antagonist. Our data suggest that SP induces NK92-MI cell cytotoxicity by directly increasing the expression of cytotoxic granules and upregulates NK92-MI cell receptor-mediated functions indirectly. Thus, SP may regulate NK cell function mainly through NK-1R.

The protective effect of hyperbaric oxygen on hearing during chronic noise exposure

A series of experiments were conducted on guinea pigs to study the protective effect of hyperbaric oxygen (HBO) on hearing during chronic repeated noise exposure. A 1/3 octave band of noise centered at 1000 Hz was used (126 dB SPL, 1 h daily for 5 d; or 108 dB SPL, 1 h daily, 5 d/week for 4 weeks). Some groups of animals were treated with HBO (2-3 ATA, 1 h duration) before noise exposure. The results indicate that inhalation of HBO (every other day) can markedly reduce noise-induced threshold shift and relieve cochlear damage. The mechanism responsible for HBO protection against noise-induced hearing damage is discussed.

Noise-induced hearing loss in iron-deficient rats

The role of iron deficiency in noise-induced hearing loss (NIHL) was evaluated in 64 rats of four different experimental groups. Iron-deficient rats (ID-rats) and normal rats (N-rats) were simultaneously exposed to a steady state white noise (20-10,000 Hz) at 110 dB SPL for 30 min. Unexposed ID- and N-rats served as controls. In N-rats the temporary threshold shifts (TTS) would have completely disappeared if the animals were allowed to survive for 72 h. No permanent threshold shift (PTS) was seen in any of the N-rats. The ultrastructural correlates in N-rats are stereocilia disarray and mitochondria swelling in outer hair cells (OHCs). The TTS in ID-rats were larger than those in the N-rats, and most ID-rats with larger threshold shifts showed varying degrees of PTSs at 11 days post-exposure. The ultrastructural correlates of NIHL in ID-rats are obvious pathology of the stereocilia, such as segmental coalescence of stereocilia of many continuous OHCs and fusion of the tips of stereocilia of OHCs, and a significant reduction of mitochondria as well as slight degeneration of nucleus in the OHCs. It is concluded that iron deficiency can provide a pathological basis for NIHL.