The prognostic significance of p21 and Her-2 gene expression and mutation/polymorphism in patients with gastric adenocarcinoma

The Role of P21 Protein Expression in Predicting Progression and Biological Behaviors of Gastric Adenocarcinomas

Background: P21 protein is a cyclin-dependent kinase inhibitor and has a crucial function as a cell cycle regulator in malignant tissues. Thus, its association with aggressive characteristics of malignant lesions is suggested. Objectives: We evaluated the expression level of P21 in gastric cancers and its association with the histopathological findings of cancer. Methods: This cross-sectional study was performed on gastric adenocarcinomas from radical gastrectomy. The histopathological examination was assessed by Hematoxylin & Eosin. The immunohistochemistry technique was then used to assess the expression of the P21 marker. Results: P21 positivity was revealed in 28 specimens of the cancerous lesions with an overall prevalence of 70.0% in our population. There was no association between P21 positivity and tumor-related characteristics, including tumor location, type, grade and stage, as well as the size of the cancerous lesion. P21 positivity could not be related to perineural or lymphovascular invasion of the tumor (P-value > 0.05). Conclusions: In our population, the expression of P21 may not be prognostic or predict tumor biological behavior among patients with gastric adenocarcinomas.

Systematic Review and Meta-analysis of TP53, HER2/ERBB2, KRAS, APC, and PIK3CA Genes Expression Pattern in Gastric Cancer

Background: With a global prevalence of about 10%, gastric cancer is among the most prevalent cancers. Currently, there has been an ongoing trend toward investigating genetic disruptions in different cancers because they can be used as a target-specific therapy. We aimed to systemically review some gene expression patterns in gastric cancer. Methods: The current systematic review was designed and executed in 2020. Scopus, PubMed, Cochrane Library, Google Scholar, web of knowledge, and Science Direct were searched for relevant studies. A manual search of articles (hand searching), reference exploring, checking for grey literature, and seeking expert opinion were also done. Results: In this review, 65 studies were included, and the expression pattern of HER2/ ERBB2, ER1/Erb1/EGFR, PIK3CA, APC, KRAS, ARID1A, TP53, FGFR2 and MET was investigated. TP53, APC, KRAS, and PIK3CA mutation cumulative frequency were 24.8 (I²=95.05, Q value=525.53, df=26, P<0.001), 7.2 (I²=89.79, Q value=48.99, df=5, P<0.001), 7.8 (I²=93.60, Q value=140.71, df=9, P=0.001) and 8.6 (I²=80.78, Q value=525.53, df=9, P<0.001) percent, respectively. Overexpression was investigated for HER1/ Erb1/EGFR, PIK3CA, APC, KRAS, ARID1A, TP53, CCND1, FGFR2, MET and MYC. The frequency of TP53 and HER2/ERBB2 were 43.1 (I²=84.06, Q value=58.09, df=9, P<0.001) and 20.8 (I²=93.61, Q value=234.89, df=15, P<0.001) percent, respectively. Conclusion: More research is encouraged to investigate the genes for which we could not perform a meta-analysis.

Polymorphisms of the AS3MT gene are associated with arsenic methylation capacity and damage to the P21 gene in arsenic trioxide plant workers

Epidemiological evidence suggests that the metabolic profiles of each individual exposed to arsenic (As) are related to the risk of cancer, coronary heart disease, and diabetes. The arsenite methyltransferase (AS3MT) gene plays a key role in As metabolism. Several single nucleotide polymorphisms in the AS3MT gene may affect both enzyme activity and gene transcription. AS3MT polymorphisms are associated with the proportions of monomethylarsenic acid (MMA) and dimethylarsenic acid (DMA) in urine as well as the incidence of cancer. P21 protein is a cyclin-dependent kinase inhibitor. Mutations of the P21 gene have been found in cancer patients. In our study, we investigate whether polymorphisms of the AS3MT gene alter As methylation capacity and adversely affect the P21 gene in arsenic trioxide plant workers. The DNA damage was examined by the quantitative polymerase chain reaction. Restriction fragment length polymorphism was used to analyze the genotype of the AS3MT gene. The results showed that DNA damage in P21 gene fragments was greater in those individuals exposed to high levels of As. There was a strong positive correlation between the DNA damage to P21 gene fragments and the percentage of MMA in urine. However, DNA damage in P21 gene fragments was negatively associated with the percentage of DMA in urine (%uDMA), primary methylation index (PMI), and secondary methylation index. We found that subjects with the rs7085104 GG or GA allele were associated with higher %uDMA and PMI and less DNA damage. The subjects with the rs11191454 GG+GA or GA allele were also associated with higher %uDMA and PMI and less DNA damage. Our results suggest that rs1191454 and rs7085104 in the AS3MT gene affect the As-induced DNA damage by altering individual metabolic efficiency.

Selective activation of tumor-suppressive MAPKP signaling pathway by triptonide effectively inhibits pancreatic cancer cell tumorigenicity and tumor growth

The mitogen-activated protein kinase (MAPK, 1K) family members ERK, JNK, and p38 play a divergent role in either promoting tumorigenesis or tumor-suppression. Activation of ERK and JNK promotes tumorigenesis; whereas, escalation of p38 inhibits carcinogenesis. As these three MAPK members are controlled by the common up-stream MAPK signaling proteins which consist of MAPK kinases (2K) and MAPK kinase kinases (3K), how to selectively actuate tumor-suppressive p38, not concurrently stimulate tumorigenic ERK and JNK, in cancer cells is a challenge for cancer researchers, and a new opportunity for novel anti-cancer drug discovery. Using human pancreatic cancer cells and xenograft mice as models, we found that a small molecule triptonide first discerningly activated the up-stream MAPK kinase kinase MEKK4, not the other two 3K members ASK1 and GADD45; and then selectively actuated the middle stream MAPK kinase MKK4, not the other two 2K members MKK3 and MKK6; and followed by activation of the MAPK member p38, not the other two members ERK and JNK. These data suggest that triptonide is a selective MEKK4-MKK4-p38 axis agonist. Consequently, selective activation of the MEKK4-MKK4-p38 signaling axis by triptonide activated tumor suppressor p21 and inhibited CDK3 expression, resulting in cancer cell cycle arrest at G2/M phase and marked inhibition of pancreatic cancer cell tumorigenic capability in vitro and tumor growth in xenograft mice. Our findings support the notion that selective activation of tumor-suppressive MEKK4-MKK4-p38-p21signaling pathway by triptonide is a new approach for pancreatic cancer therapy, providing a new drug candidate for development of novel anti-cancer therapeutics.

Expression and prognostic value of miR-92a in patients with gastric cancer

MicroRNA (miR)-92 expression is often aberrant in human cancers. However, its expression in gastric carcinoma and its relation to clinicopathological features and prognosis are unclear.Tissue microarrays were constructed from 180 patients with gastric cancer (GC), who were undergoing radical resection. MiR-92a expression was detected using miRNA-locked nucleic acid in situ hybridization, and its correlation with clinicopathological features and overall survival was analyzed. MiR-92a expression was decreased in 13.9 % (25/180) of GC, increased in 81.1 % (146/180), and unchanged in 5.0 % (9/180), compared with paracancerous normal tissue (P < 0.001). Univariate analysis showed that high miR-92a expression, tumor stage, tumor status, node status, and tumor size were significant negative prognostic predictors for overall survival in patients with GC (P < 0.001, P < 0.001, P = 0.008, P < 0.001, and P = 0.001, respectively). High miR-92a expression still remained a significant predictor of shorter survival in stage II (n = 56, P = 0.001) and stage III (n = 92, P = 0.009) GC. Multivariate regression analysis demonstrated that tumor status (hazard ratio [HR], 3.10; 95 % confidence interval [CI], 1.51-6.37; P = 0.002), stage (HR, 3.54; 95 % CI, 1.65-7.63; P = 0.000), lymph node metastasis (HR, 2.83; 95 % CI, 1.88-4.28; P = 0.000), high expression of miR-92a (HR, 2.94; 95 % CI, 2.01-4.31; P = 0.000), and tumor size (HR, 2.34; 95 % CI, 1.45-3.79; P = 0.002) predicted shorter OS.High expression of miR-92a compared with adjacent normal tissues was associated with shorter OS. MiR-92a may thus be useful for evaluating prognosis and may provide a novel treatment target in patients with GC.

Biomarkers for gastric cancer: Progression in early diagnosis and prognosis (Review)

Gastric cancer is one of leading causes of cancer-related mortality worldwide and is a notable disease due to its heterogeneity. Recently, numerous studies have investigated the molecular basis of gastric cancer, involving the alteration of pathogenesis, and invasion and metastasis. With the development of modern technologies, various novel biomarkers had been identified that appear to possess diagnostic and prognostic value; therefore, the present review describes our current knowledge of biomarkers for the early diagnosis and prognosis of gastric cancer. Classic biomarkers for gastric cancer diagnosis include carcinoembryonic antigen and cancer antigen 19-9, while microRNA and DNA hypomethylation are proposed as novel biomarkers. Excluding classical biomarkers, biomarkers for determining the progression and prognosis of gastric cancer focus on targeting microRNAs, epigenetic alterations and genetic polymorphisms.

BAX and CDKN1A polymorphisms correlated with clinical outcomes of gastric cancer patients treated with postoperative chemotherapy

This study aims to examine the correlation between two single nucleotide polymorphisms (SNPs) of apoptosis-related genes and clinical outcomes in gastric cancer. A total of 221 patients with stage T2 and T3 gastric cancer treated with postoperative chemotherapy between 2003 and 2008 were retrospectively collected in this study to explore the association of rs4645878 located in BAX gene and rs1801270 located in CDKN1A gene with survival, recurrence, and toxicity to chemotherapy. Additionally, immunohistochemistry was used to detect the BAX expression in gastric cancer tissues. Patients carrying at least one variant genotype in BAX SNP (rs4645878) showed a significantly increased recurrence risk [hazard ratio (HR) 2.63; 95 % confidence internal (95 % CI) 1.71-4.03] and poor survival (HR 2.89; 95 % CI 1.88-4.44). Moreover, the recurrence and survival rate in patients with GA genotype was 72.7 and 24.7 %, respectively, compared with total recurrence rate of 54.8 %, P = 0.006, and compared with total survival rate of 46.6 %, P = 0.001. In addition, the GA genotype was related to lower BAX expression in gastric cancer tissues. The CDKN1A (rs1801270) mutant genotype was associated with a significantly decreased risk of hematologic toxicity [odds ratio (OR) 0.28; 95 % CI 0.12-0.63]. SNPs located in BAX and CDKN1A genes are closely associated with clinical outcomes in patients with gastric cancer.

The effect of Helicobacter pylori CagA on the HER-2 copy number and expression in gastric cancer

We investigated whether Helicobacter pylori (H. pylori) CagA contributes to the DNA copy change and mRNA transcript expression of the HER-2 gene and, consequently, affects HER-2 protein expression to evaluate the significance of CagA and HER-2 amplification in gastric cancer. We used the AGS and MKN1 gastric cancer and HFE-145 immortalized non-neoplastic gastric mucosa cell lines. We also confirmed the effects of CagA on HER-2 expression in human gastric cancer tissues and gastric mucosal tissues of H. pylori infected C57BL/6 mice. Ectopic CagA expression in AGS, MKN1 and HFE-145 cells showed a significant increase in HER-2 gene copy number and expression. The gastric mucosae of H. pylori infected C57BL/6 mice also showed increased HER-2 DNA copy number and protein expression. In addition, CagA expression was detected in 17 (56.7%) of 30 gastric cancer tissues, and eight (47%) of them showed HER-2 DNA amplification of more than two-fold. In immunohistochemistry, HER-2 overexpression was detected in 12 (40%) of 30 gastric cancers and a positive correlation was observed among DNA copy number, the mRNA transcript, and protein expression of the HER-2 gene in gastric cancer (P<0.05). These results suggest that H. pylori CagA may induce overexpression of the HER-2 protein by increasing HER-2 DNA and mRNA copy number.

Expression of CD24, p21, p53, and c-myc in alpha-fetoprotein-producing gastric cancer: Correlation with clinicopathologic characteristics and survival

BACKGROUND AND OBJECTIVE

The aim of this study was to evaluate the expression of CD24, p21, p53, and c-myc in lesions of patients with Alpha-Fetoprotein (AFP)-producing gastric cancer and their correlation with clinicopathological features and prognosis.

METHODS

One hundred and four patients with AFP-producing gastric cancer were included into this study. The levels of CD24, p21, p53, and c-myc were examined by immunohistochemistry.The prognostic value of these biological markers and the correlation between biological markers and clinicopathological factors were investigated.

RESULTS

The percentages of positive expression of CD24, p21, p53, and c-myc were 31.7%, 77.9%, 75.0%, and 66.3%, respectively. CD24 expression correlated with histological grade (P = 0.045) and Lauren type (P = 0.006); p21expression with Borrmann type (P = 0.035); c-myc expression with Borrmann type (P = 0.029). p21 expression was related with poor survival in univariate analysis (P = 0.016). Multivariate analysis showed that p21 expression, vascular invasion, and pathological stage were defined as independent prognostic factors.

CONCLUSION

The expression of p21 was an independent prognostic factor for patients with AFP-producing gastric cancer.

Hepatocyte expression of the senescence marker p21 is linked to fibrosis and an adverse liver-related outcome in alcohol-related liver disease

Background and Aim

Alcohol-related liver disease (ALD) remains a leading cause of liver-related morbidity and mortality. Age, fibrosis stage, MELD score and continued alcohol consumption predict outcome in everyday clinical practice. In previous studies increased hepatocyte nuclear area and hepatocyte expression of p21, both markers of senescence, were associated with increased fibrosis stage and a poor outcome in non-alcohol-related fatty liver disease, while increased hepatocyte nuclear area was related to liver dysfunction in ALD cirrhosis. This study, therefore, investigated the pattern of hepatocyte cell cycle phase distribution and hepatocyte p21 expression in relation to outcome in ALD.

Methods

Liver sections from two cohorts were studied. The first comprised 42 patients across the full spectrum of ALD. The second cohort comprised 77 patients with ALD cirrhosis. Immunohistochemistry assessed hepatocyte expression of cell cycle phase markers and p21. Regenerating liver (n=12) and “normal” liver sections (n=5) served as positive and negative controls, respectively.

Results

In the first cohort there was little cell cycle progression beyond G₁/S phase and increased hepatocyte p21 expression (p<0.0001), which correlated independently with fibrosis stage (p=0.005) and an adverse liver-related outcome (p=0.03). In the second cohort, both hepatocyte p21 expression (p<0.001) and MELD score (p=0.006) were associated independently with an adverse liver-related outcome; this association was stronger with hepatocyte p21 expression (AUROC 0.74; p=0.0002) than with MELD score (AUROC 0.59; p=0.13). Further, hepatocyte p21 expression co-localised with increased hepatic stellate cell activation.

Conclusions

The findings are consistent with impaired cell cycle progression beyond the G₁/S phase in ALD. The striking independent associations between increased hepatocyte p21 expression and both fibrosis stage and an adverse liver-related outcome in both cohorts suggests hepatocyte senescence plays an important role in ALD. Measuring hepatocyte p21 expression is simple and cheap and in this series was a useful measure of long-term prognosis in ALD.