Association between p53 immunostaining and cigarette smoking in squamous cell carcinoma of the esophagus

Association Between Smoking and p53 Mutation in Oesophageal Squamous Cell Carcinoma: A Meta-analysis

AIMS

Several studies have evaluated the association between smoking and p53 mutation in oesophageal squamous cell carcinoma (ESCC), but the conclusions are inconsistent. The aim of the present study was to carry out a meta-analysis evaluating the relationship between smoking and p53 mutation in patients with ESCC.

MATERIALS AND METHODS

Eligible studies were identified through searches in PubMed and EMBASE. The odds ratio with 95% confidence interval was used to assess the association. In total, 20 studies were identified that met the selection criteria; these studies were analysed using STATA 12.0 software.

RESULTS

The 20 studies identified comprised 1524 ESCC patients, of whom 72.97% were smokers and 27.03% were non-smokers. The pooled odds ratio of p53 mutation in ESCC for any cigarette smoking versus no smoking was 1.28 (95% confidence interval=0.88-1.88). The estimated odds ratios were 1.06 (95% confidence interval=0.56-2.00, based on five studies, 129 light smokers and 70 non-smokers) for light smoking and 2.01 (95% confidence interval=1.12-3.60, based on five studies, 223 heavy smokers and 73 non-smokers) for heavy smoking.

CONCLUSION

The results of our meta-analysis indicate an overall positive relationship between heavy smoking and p53 mutation in ESCC. Heavy smokers with ESCC have a higher risk for p53 mutation than non-smokers. Large-scale clinical studies are still needed to draw a more precise conclusion.

Association of p53/p21 expression and cigarette smoking with tumor progression and poor prognosis in non-small cell lung cancer patients

Non-small cell lung cancer (NSCLC) accounts for approximately 80-85% of all lung cancer cases. Cigarette smoking is the number one risk factor which is attributed to more than four out of five cases of lung cancers. The prognostic impact of cell cycle regulation-associated tumor suppressors including p53 and p21 for NSCLC is still controversial. In the present study, we examined p53 and p21 expression using immunoblotting in tumor and adjacent non-cancerous tissues from NSCLC patients. Moreover, tissue microarrays (TMAs) including 150 specimens was used to examine p53 and p21 expression by immunohistochemical staining (IHC). The association between p53/p21 and various clinicopathological characteristics was evaluated. Kaplan-Meier overall survival was used to analyze the association between p53/p21 expression and prognosis of NSCLC patients, as well as the association of cigarette smoking with p53/p21 expression and prognosis. The results of the immunoblotting showed that expression of p53 and p21 in tumor tissues was significantly higher than that in the matched adjacent non-cancerous tissues (P<0.001 and P<0.05, respectively). The IHC results showed that 50.67% of the cases had high expression of p21; however, the percentage of patients having high expression of p53 was 31.3%. Univariate and Cox regression models were used to evaluate the factors related to prognosis with p53 and p21 expression. Multivariate analysis indicated that p53 expression was an independent prognostic factor for NSCLC (P=0.005), while p21 could not serve as an independent prognostic factor (P=0.123). In addition, smoking history was closely related to lung cancer risk (P=0.041), but could not be an independent assessment factor (P=0.740). In this study, we further demonstrated the association of p53/p21 expression and cigarette smoking. Our results suggest that cigarette smoking and overexpression of p53 or p21 are associated with poor prognosis. The combination of p53/p21 expression and smoking history may be a useful biomarker for tumor progression and prognosis of NSCLC patients.

Elevated p53 expression levels correlate with tumor progression and poor prognosis in patients exhibiting esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the most common histological subtype of esophageal cancer and one of the most aggressive types of malignancy, with a high rate of mortality. Early diagnosis and treatment may improve the prognosis of ESCC and, thus, survival rates. As a significant tumor suppressor, p53 is closely associated with apoptosis and the differentiation of cancer cells. The present study evaluated the expression levels of the p53 protein and the clinical significance in patients presenting with ESCC. The p53 protein expression level of 64 paired ESCC and tumor-adjacent normal tissues was evaluated using western blot analysis. In addition, immunohistochemistry (IHC) was performed to detect the p53 expression level in specimens from 118 paraffin-embedded cancerous tissues. The correlation of the p53 expression level with the clinicopathological parameters and prognosis of the ESCC patients was also analyzed. The p53 protein was identified to be highly expressed in the ESCC tissue, with western blot analysis demonstrating that the expression level of p53 in the cancerous tissue was 1.89 times that of the tumor-adjacent normal tissue (P<0.001); furthermore, IHC indicated that there was a marked positive expression of p53 in the ESCC tissue (49.15%). The expression level of p53 protein was identified to be significantly correlated with the tumor grade (P<0.001), N stage (P=0.010). Additionally, the higher level of p53 expression was found to be associated with a poor survival rate in the ESCC patients (P=0.0404). The univariate analysis showed that the survival time of patients was significantly correlated with the T stage (RR=3.886, P<0.001), N stage (lymph node metastasis; RR=3.620, P<0.001) and TNM stage (RR=3.576, P<0.001). Furthermore, the multivariate analysis revealed that the T stage (RR=3.988, P<0.001) and N stage (RR=4.240, P=0.004) significantly influenced the overall survival of the ESCC patients.

p53 immunohistochemical expression and patient prognosis in esophageal squamous cell carcinoma

It is generally accepted that overexpression of p53 protein is associated with poor prognosis in gastric, lung, and other types of cancer. However, the prognostic significance of p53 aberrations in esophageal cancer remains unclear. This is the largest study (n = 266) examining clinical and prognostic features of p53 immunohistochemical expression in esophageal squamous cell carcinoma. In 139 (52%) esophageal tumors, nuclear immunoreactivity for p53 protein was detected. p53 aberrant expression was not associated with sex, age, preoperative treatment, TNM stage, or histological grade. Furthermore, p53 expression did not correlate with disease-free survival (P = 0.73) or overall survival (P = 0.62). In addition, no significant modification effect by any of the covariates in the survival analysis was observed (all P > 0.15). In conclusion, our large-scale study demonstrates that p53 expression has no impact on the prognosis of esophageal squamous cell carcinoma.

Specific-mutational patterns of p53 gene in bladder transitional cell carcinoma among a group of Iraqi patients exposed to war environmental hazards

Background

To unfold specific-mutational patterns in TP53 gene due to exposures to war environmental hazards and to detect the association of TP53 gene alteration with the depth of bladder cancer.

Methods

Twenty-nine bladder carcinomas were analyzed for TP53 alterations. PCR-single strand conformational polymorphism analysis, DNA sequencing and immunohistochemical analysis using monoclonal mouse anti-human p53 antibody (Clone DO-7) were employed.

Results

TP53 gene mutations occurred in 37.9% of the cases while TP53 overexpression occurred in 58.6%. Both of them were associated with deep invasive-tumors. Single mutations were seen in 63.6%, whereas only 27.3% have shown double mutations. Four mutations were frameshifted (30.8%); two of them showed insertion A after codon 244. There was no significant association between TP53 mutations and protein overexpression (P>0.05), while a significant association was observed between TP53 alterations and tumors progression (P ≤ 0.01).

Conclusion

The infrequent TP53mutations, especially insertion A and 196 hotspot codon, may represent the specific-mutational patterns in bladder carcinoma among the Iraqi patients who were exposed to war environmental hazards. TP53 alteration associated with bladder cancer progression should be analyzed by both mutational and protein expression analysis.

Association of p53/p21 expression with cigarette smoking and prognosis in esophageal squamous cell carcinoma patients

AIM: To investigate the expression of p53 and p21 and associations with possible risk factors, such as cigarette smoking, in esophageal squamous cell carcinoma (ESCC) in northeastern Iran, a region with a high incidence of ESCC.

METHODS: The expression of p53 and p21 proteins was investigated immunohistochemically in tumor tissue from 80 ESCC patients and in 60 available paraffin-embedded blocks of adjacent normal specimens from the cases, along with normal esophageal tissue from 80 healthy subjects.

RESULTS: Positive expression of p53 protein was detected in 56.2% (45/80) of ESCC cases, and in none of the normal esophageal tissue of the control group (P < 0.001). Furthermore, 73.8% (59/80) of ESCC cases and 43.8% (35/80) of controls had positive expression of p21 protein (P < 0.001). Cigarette smoking was significantly associated with p53 over-expression in ESCC cases (P = 0.010, OR = 3.64; 95% CI: 1.32-10.02). p21 over-expression was associated with poorer clinical outcome among the ESCC patients (P = 0.009).

CONCLUSION: Over-expression of p53 in association with cigarette smoking may play a critical role in ESCC carcinogenesis among this high-risk population of northeastern Iran. Furthermore, p21 over-expression was found to be associated with poor prognosis, specifically in the operable ESCC patients.

Receptor-mediated tobacco toxicity: regulation of gene expression through alpha3beta2 nicotinic receptor in oral epithelial cells

Tobacco is a known cause of oral disease but the mechanism remains elusive. Nicotine (Nic) is a likely culprit of pathobiological effects because it displaces the local cytotransmitter acetylcholine from the nicotinic receptors (nAChRs) expressed by oral keratinocytes (KCs). To gain a mechanistic insight into tobacco-induced morbidity in the oral cavity, we studied effects of exposures to environmental tobacco smoke (ETS) versus equivalent concentration of pure Nic on human and murine KCs. Both ETS and Nic up-regulated expression of cell cycle and apoptosis regulators, differentiation marker filaggrin, and signal transduction factors at both the mRNA and protein levels. These changes could be abolished in cultured human oral KCs transfected with anti-alpha3 small interfering RNA or treated with the alpha3beta2-preferring antagonist alpha-conotoxin MII. Functional inactivation of alpha3-mediated signaling in alpha3-/- mutant KCs prevented most of the ETS/Nic-dependent changes in gene expression. To determine relevance of the in vitro findings to the in vivo situation, we studied gene expression in oral mucosa of neonatal alpha3+/+ and alpha3-/- littermates delivered by heterozygous mice soon after their exposures to ETS or equivalent concentration of pure Nic in drinking water. In addition to reverse transcriptase-polymerase chain reaction and Western blot, the ETS/Nic-dependent alterations in gene expression were also detected by semiquantitative immunofluorescence assay directly in KCs comprising murine oral mucosa. Only wild-type mice consistently developed significant (P < 0.05) changes in the gene expression. These results identified alpha3beta2 nAChR as a major receptor mediating effects of tobacco products on KC gene expression. Real-time polymerase chain reaction demonstrated that in all three model systems the common genes targeted by alpha3beta2-mediated ETS/Nic toxicity were p21, Bcl-2, NF-kappaB, and STAT-1. The expression of the nAChR subunits alpha5 and beta2 and the muscarinic receptor subtypes M(2) and M(3) was also altered. This novel mechanism offers innovative solutions to ameliorate the tobacco-related cell damage and intercede in disease pathways, and may shed light on general mechanisms regulating and driving tobacco-related morbidity in human cells.

Genetic susceptibility and environmental factors of esophageal cancer in Xi’an

AIM: To analyse the role of genetic susceptibility and environmental factors in the process of esophageal cancer (EC) formation in Xi’an, China.

METHODS: A hospital based case-control study, combined with molecular epidemiological method, was carried out. A total of 127 EC cases and 101 controls were interviewed with questionnaires containing demographic items, habit of tobacco smoking, alcohol drinking, and family history of EC. Polymorphism of CYP1A1 and GSTM1 of 127 EC cases and 101 controls were detected by PCR method. The interactions between genetic susceptibility and environmental factors were also discussed.

RESULTS: Tobacco smoking, alcohol drinking and a family history of EC were risk factors for EC with an OR of 2.04 (95%CI 1.15-3.60), 3.45(95%CI 1.74-6.91), 3.14 (95%CI 1.28-7.94), respectively. Individuals carrying CYP1A1 Val/Val genotype compared to those with CYP1A1 Ile/Ile genotype had an increased risk for EC (OR 3.35, 95%CI 1.49-7.61). GSTM1 deletion genotype was a risk factor for EC (OR1.81, 95%CI 1.03-3.18). Gene-environment interaction analysis showed that CYP1A1 Val/Val genotype, GSTM1 deletion genotype had synergetic interactions with tobacco smoking, alcohol drinking and family history of EC.

CONCLUSION: Tobacco smoking, alcohol drinking and a family history of EC are risk factors for EC. CYP1A1 Val/Val and GSTM1 deletion genotypes are genetic susceptibility biomarkers for EC. There are synergic interactions between genetic susceptibility and environmental factors.

Molecular and biologic basis of upper gastrointestinal malignancy--esophageal carcinoma

Esophageal cancer is one of the most deadly forms of gastrointestinal cancer. Even though the incidence of esophageal adenocarcinoma has been rising in Western populations over the past two decades, esophageal squamous cell carcinoma remains the predominant type of esophageal malignancy in the remainder of the world. With the recent advances in molecular biology, high-output genome wide screening has provided comprehensive profiles of molecular alterations in human esophageal carcinomas. The elucidation of the basic mechanisms of esophageal carcinogenesis brings with it the promise of developing treatment and preventive strategies that are based on the molecular biology of these tumors. The genetic alterations discussed in this article are not unique to the formation of esophageal carcinomas and represent only a fraction of the molecular changes found in these tumors. The goal of this article is to provide the clinician with a useful conceptual basis for evaluating studies on the molecular mechanisms underlying the development of esophageal carcinomas.

Relationship of tobacco smoking CYP1A1 GSTM1 gene polymorphism and esophageal cancer in Xi'an

AIM

To analyze the association of tobacco smoking polymorphism of CYP1A1 (7th exon) and GSTM1 genotype and esophageal cancer(EC) in Xi'an.

METHODS

A hospital based case-control study, with molecular epidemiological method, was carried out. Polymorphism of CYP1A1 and GSTM1 of samples from 127 EC cases and 101 controls were detected by PCR method.

RESULTS

There were no significant difference of age and gender between cases and controls. Tobacco smoking was the main risk factor OR=1.97;95% CI=1.12-3.48 for EC in Xi'an. The proportions of CYP1A1 Ile/Ile, Ile/Val and Val/Val gene types in cases and controls was 19.7% 45.7% 34.6% and 30.7%,47.5%, 21.8% respectively(P=0.049). Individuals with CYP1A1 Val/Val genotype compared to those with CYP1A1 Ile/Ile genotype had higher risk for EC increased (OR=2.48, 95%CI=1.12-5.54). The proportions of GSTM1 deletion genotype in cases and controls were 58.3% and 43.6%(OR=1.81, 95%CI=1.03-3.18, P=0.028). Analysis of gene-environment interaction showed that tobacco smoking and CYP1A1 Val/Val genotype; tobacco smoking and GSTM1 deletion genotype had synergism interaction respectively. Analysis of gene-gene interaction did not find synergistic interaction between these two genes. But in GSTM1 deletion group there was significant difference of distribution of CYP1A1 genotype between cases and controls (P=0.011).

CONCLUSION

CYP1A1 Val/Val and GSTM1 deletion genotypes are genetic susceptibility biomarkers for EC. The risk increases, when person with CYP1A1 Val/Val and/or GSTM1 deletion genotype. And these two-metabolic enzymes seem to have interactions with tobacco smoking, in which the mechanism still needs further study.