Concurrent overexpression of serum p53 mutation related with Helicobacter pylori infection

T-17, a spirostanol saponin, inhibits p53-independent proliferation and p53-dependent migration of gastric cancer cells

The p53 tumor suppressor gene contributes to a series of life processes of cells. Previously, we have shown that T-17, a spirostanol saponin extracted from Tupistra chinensis induces cell cycle arrest, apoptosis and autophagy in gastric cancer cells. The p53 is essential in the cell cycle arrest induced by T-17, however, the effect of p53 on T-17-induced apoptosis and autophagy is still unclear. Here, our study shows that T-17 has no difference in the sensitivity of gastric cancer cells with different p53 status. By transfecting p53 siRNA into AGS cells (p53 wild type cells) or wild-type p53 into KATO-III cells (p53 deficiency cells), T-17 was found to induce apoptosis and autophagy in gastric cancer cells in a p53-independent manner. Pre-treatment with N-acetylcysteine (NAC, a ROS scavenger) demonstrated that reactive oxygen species (ROS) mediated T-17-induced p53-independent apoptosis. Besides, T-17 induces apoptosis and autophagy in gastric cancer cells by decreasing the expression of HMGB1, also in a p53-independent manner. But when we detected the inhibitory effect of T-17 on gastric cancer cell migration, it was found that p53 is essential. These experimental results showed that T-17 induced apoptosis and autophagy in gastric cancer cells in a p53-independent manner, but inhibited the migration of gastric cancer cells in a p53-dependent manner. Our research indicates that T-17 is a potential candidate for gastric cancer and provides support for better utilization of Tupistra chinensis.

The occupational risk of Helicobacter pylori infection: a systematic review

PURPOSE

The aim of this systematic review was to describe the prevalence of Helicobacter pylori infection in specific occupational groups and to compare them with the general population.

METHODS

We searched PubMed® to identify original studies reporting the prevalence of H. pylori infection in occupational groups. The differences between occupational groups and the general population were analyzed taking into account the direction and statistical significance of the differences observed when comparing each occupational group with a reference group (either recruited in the same study or using an external comparator).

RESULTS

A total of 98 studies addressing the prevalence of H. pylori infection in occupational groups were included in the systematic review. Overall, health professionals showed a significantly higher prevalence of H. pylori infection than the general population, especially among those working at gastrointestinal units. Similar results were found in subjects involved in agricultural, forestry and fishery, as well as in sewage workers, miners, and workers at institutions for the intellectually disabled, although differences were less pronounced.

CONCLUSIONS

Our results show an occupational risk of H. pylori infection supporting the role of oral-oral, fecal-oral, and zoonotic transmission. Studies comparing specific occupational groups with adequate comparators may contribute to better identify groups at higher risk of infection. The recognition of this infection as an occupational disease would result in early detection and treatment, as well as prevention and control of its transmission in workplaces.

p53, a potential predictor of Helicobacter pylori infection-associated gastric carcinogenesis?

Helicobacter pylori (H. pylori) is an ancient and persistent inhabitant of the human stomach that is closely linked to the development of gastric cancer (GC). . Emerging evidence suggests that H. pylori strain interactions with gastric epithelial cells subvert the best- characterized p53 tumour suppressor pathway. A high prevalence of p53 mutations is related to H. pylori infection. H. pylori also accelerates p53 protein degradation by disturbing the MDM2-P53 feedback loop. Additionally, H. pylori triggers the alteration of other p53 isoforms. Dysregulation of p53 by H. pylori infection contributes to gastric carcinogenesis by mediating cell proliferation and apoptosis. This review focuses on the regulation of p53 in H. pylori infection-associated GC.

Horizontal gene transfers with or without cell fusions in all categories of the living matter

This article reviews the history of widespread exchanges of genetic segments initiated over 3 billion years ago, to be part of their life style, by sphero-protoplastic cells, the ancestors of archaea, prokaryota, and eukaryota. These primordial cells shared a hostile anaerobic and overheated environment and competed for survival. "Coexist with, or subdue and conquer, expropriate its most useful possessions, or symbiose with it, your competitor" remain cellular life's basic rules. This author emphasizes the role of viruses, both in mediating cell fusions, such as the formation of the first eukaryotic cell(s) from a united crenarchaeon and prokaryota, and the transfer of host cell genes integrated into viral (phages) genomes. After rising above the Darwinian threshold, rigid rules of speciation and vertical inheritance in the three domains of life were established, but horizontal gene transfers with or without cell fusions were never abolished. The author proves with extensive, yet highly selective documentation, that not only unicellular microorganisms, but the most complex multicellular entities of the highest ranks resort to, and practice, cell fusions, and donate and accept horizontally (laterally) transferred genes. Cell fusions and horizontally exchanged genetic materials remain the fundamental attributes and inherent characteristics of the living matter, whether occurring accidentally or sought after intentionally. These events occur to cells stagnating for some 3 milliard years at a lower yet amazingly sophisticated level of evolution, and to cells achieving the highest degree of differentiation, and thus functioning in dependence on the support of a most advanced multicellular host, like those of the human brain. No living cell is completely exempt from gene drains or gene insertions.