Difference of p53AIP1 mRNA expression in gastric mucosa between patients with gastric cancer and chronic gastritis infected with Helicobacter pylori

Prognostic Factors of Survival in Patients With Gastric Cancer Under 45 Years Old Treated With Surgery in a Single Center in Mexico City

Introduction Gastric cancer is a significant major global health concern, particularly prevalent in Asia. In recent years, a large number of new cases have been diagnosed worldwide, leading to a substantial number of deaths. The disease tends to present more aggressively in these cases, leading to debates about the prognosis and survival outcomes. Nonetheless, research has shown that survival rates improve significantly when the tumor is completely surgically resected. Materials and methods This retrospective study included patients between 16 and 45 years old, diagnosed with gastric cancer, with the support of the pathology department, who underwent surgery in the upper GI service, in the period from January 2006 to December 2012. Data collected encompassed variables such as gender, age, tumor size, type of surgery, overall survival, disease-free period, type and histological degree of the tumor, clinical stage of the cancer, and R0 resection (curative resection). All patients with a confirmed diagnosis of gastric cancer were included and treated with surgery and D1 limited dissection or extended D2 dissection. Patients who have received chemotherapy prior to surgical treatment and those who have been surgically treated outside the XXI Century National Medical Center were excluded. Results A total of 104 patients were included; the predominant histological type was diffuse adenocarcinoma accounting for 79.8% and 81.7% of the cases were histological grade 3. The most common clinical stage was IIIA in 41.3% of the cases. In 53.8% of the cases, we obtained an R0 resection. D2 lymphadenectomy was performed in 53.8% of the cases, with an overall survival rate of 82.69%. Significant prognostic factors for survival included T4 depth with an increase in risk for mortality (OR: 25.93; 95% CI: 6.41-53.54; p=0.001), lymph node status (OR: 14.76; 95% CI: 4.6-46.83; p<0.001), and size greater than 5 cm (OR: 1.8; 95% CI: 0.61-6.35; p<0.001). Conclusions Gastric cancer is more common in adults aged above 60 years old, but the incidence in young adults under 45 years old has been increasing. Although young gastric cancer patients present with more aggressive tumor behavior, these patients can have similar or even better overall survival compared to older patients, being 35% in some cases, especially in the resectable setting. Further research is still needed to fully characterize the unique biology and optimal management of gastric cancer in young adults.

Association of p53 Gene Mutation With Helicobacter pylori Infection in Gastric Cancer Patients and Its Correlation With Clinicopathological and Environmental Factors

BACKGROUND

Gastric cancer is also a leading cancer in Bangladesh like that of the global incidences. It is speculated that environmental, bacterial infection and molecular factors might have been carrying the key role of rising trend of the disease. This study was aimed to investigate the association of mutated p53 gene with of Helicobacter pylori (H. pylori) infection, clinicopathological and some environmental factors of the gastric cancer patients.

METHODS

This cross-sectional study was carried out from January 2015 to December 2016 in a specialized cancer hospital of Bangladesh. Patients were selected randomly who were admitted for surgical intervention after diagnosis as adenocarcinoma of the stomach and physically fit for surgery. After admission proper evaluation of the patients was done. Tissue sample from the gastrectomy specimen along with the blood sample was sent to the related laboratories. After DNA extraction for p53, exons 5 and 6, they were adjusted for proper primer designing. Appropriate sequencing analysis of the result was done. Status of p53 was investigated to see their association with the result of the H. pylori, age and sex, tumor status, smoking and extra salt intake of the patients. Result of the study was calculated and analyzed by Chi-square and binomial logistic regression to find the association amongst them.

RESULTS

Among the 71 patients, mean age was 52.96 years old, male: female ratio were 48:23, age group above 41 years were 53 (74.6%), proliferative and ulceroproliferative group of the tumor dominated (87.3%). There were 52 cases with (73.2%) p53 mutation. Among the 51 H. pylori positive cases, 41 (80%) had p53 mutation (P = 0.033). Tumor size and lymph node status were found to be associated with the gene mutation (P = 0.05). Age also had strong correlation with the mutation (P = 0.015). Gene mutation was found mostly among the younger (≤ 40 years) group of patients (94.4%). Patient with extra salt intake was also found related with the mutation (P = 0.03).

CONCLUSIONS

Environmental and genetic factors seem to be risk factors for gastric cancer in Bangladesh. Nationwide anti H. pylori drive and further molecular research could elicit the other risk factors which might help to reduce the gastric cancer incidences in the country after taking appropriate measures.

Genetic polymorphisms in DNA repair genes XPC, XPD, and XRCC4, and susceptibility to Helicobacter pylori infection-related gastric antrum adenocarcinoma in Guangxi population, China

Genetic polymorphisms in DNA repair genes may influence individual variation in DNA repair capacity, which may be associated with risk of gastric antrum adenocarcinoma (GAA) related to Helicobacter pylori infection. This study, including 361 GAAs and 616 controls without any evidence of tumors, was designed to evaluate the association between the polymorphisms of DNA repair genes XPC Ala499Val (RS#2228000) and Lys939Gln (RS#2228001), XPD Lys751Gln (RS#13181), and XRCC4 Ala247Ser (RS#3734091) and Ser298Asn (RS#1805377), and GAA risk for Guangxi population by means of TaqMan-PCR analysis. Increased risks of GAA were found for individuals with H. pylori positive [odds ratio (OR), 2.48; 95% confidence interval (CI), 1.84-3.33] or cagA positive (OR, 7.34; 95% CI, 5.46-9.87). No differences were observed among the studied groups with regard to the genotype distribution of XPC codons 499 and 939 and of XRCC4 codon 247; but XPD codon 751 genotypes with Gln [ORs (95% CI) were 2.67 (1.98-3.58) and 3.97 (2.64-5.99) for Lys/Gln and Gln/Gln, respectively] and XRCC4 codon 298 genotypes with Asn [ORs (95% CI) were 3.01 (2.21-4.10) and 4.78 (3.24-7.05) for Ser/Asn and Asn/Asn, respectively] increased the risk of GAA. Interestingly, there was an interactive effect between the risk genotypes of these two genes and cagA-positive status in the GAA risk (OR(interact) = 2.05 and 2.08, respectively). However, we did not find the gene-H. pylori-status interaction effects on the risk of GAA (P(interact) > 0.05). The results suggested that the polymorphisms of XPD codon 751 and XRCC4 codon 298 are associated with an increased risk of developing H. pylori-related GAA among Guangxi population.

Adenovirus Ad-p53AIP1-mediated gene therapy and its regulation of p53-MDM2 interactions

We generated replication-defective adenovirus Ad-p53AIP1 and studied its anti-tumor efficacy both in vitro and in vivo. We demonstrated that Ad-p53AIP1 infection elicited high levels of p53AIP1 expression in cancer cells. We also found that Ad-p53AIP1 expression induced marked apoptosis and cell cycle arrest in HepG2 cells. Moreover, Ad-p53AIP1 infection significantly inhibited the tumorigenesis of 4T1 mouse mammary cancer cells in vivo. In particular, we discovered that p53AIP1 overexpression up-regulated the protein levels of p53 in HepG2 cells, which was accompanied by down-regulation of MDM2 mRNA and protein, suggesting an interaction between MDM2 and p53 in p53AIP1-induced apoptosis and cell cycle arrest. Our data demonstrated the feasibility of Ad-p53AIP1-mediated cancer gene therapy. p53AIP1-induced up-regulation of p53 protein through MDM2 suggests that p53AIP1 gene therapy may be more advantageous in tumors expressing high levels of oncoprotein MDM2 or having a mutation in MDM2 inhibitor p16INK4.

Helicobacter pylori and gastric cancer

Helicobacter pylori is now well known as an important pathogen related to the development of gastric cancer. However, some clinicians still doubt the causal association of H. pylori with the development of gastric cancer. To summarize the recent clinical data on the link between H. pylori and gastric cancer, we reviewed related articles published over the past 3 years, after the award of the Nobel Prize for Physiology or Medicine to Drs. J.R. Warren and B.J. Marshall for the first culture and isolation of H. pylori and the investigation of their relevance to peptic ulcer disease. This updated summary of the relationship between H. pylori and gastric cancer highlights the strong link between the organism and the development of gastric cancer, and suggests eradication of this bacterial infection as a possible prophylactic measure against the development of this lethal malignancy. At present, clinicians and researchers in the field emphasize the strong need for H. pylori eradication from the human stomach.