Accurate prediction of acute pancreatitis severity based on genome-wide cell free DNA methylation profiles.

BACKGROUND: Patients with severe acute pancreatitis (SAP) have a high mortality, thus early diagnosis and interventions are critical for improving survival. However, conventional tests are limited in acute pancreatitis (AP) stratification. We aimed to assess AP severity by integrating the informative clinical measurements with cell free DNA (cfDNA) methylation markers. METHODS: One hundred and seventy-five blood samples were collected from 61 AP patients at multiple time points, plus 24 samples from healthy individuals. Genome-wide cfDNA methylation profiles of all samples were characterized with reduced representative bisulfite sequencing. Clinical blood tests covering 93 biomarkers were performed on AP patients within 24 h. SAP predication models were built based on cfDNA methylation and conventional blood biomarkers separately and in combination. RESULTS: We identified 565 and 59 cfDNA methylation markers informative for acute pancreatitis and its severity. These markers were used to develop prediction models for AP and SAP with area under the receiver operating characteristic of 0.92 and 0.81, respectively. Twelve blood biomarkers were systematically screened for a predictor of SAP with a sensitivity of 87.5% for SAP, and a specificity of 100% in mild acute pancreatitis, significantly higher than existing blood tests. An expanded model integrating 12 conventional blood biomarkers with 59 cfDNA methylation markers further improved the SAP prediction sensitivity to 92.2%. CONCLUSIONS: These findings have demonstrated that accurate prediction of SAP by the integration of conventional and novel blood molecular markers, paving the way for early and effective SAP intervention through a non-invasive rapid diagnostic test.

[Hydrogen-rich water improves progressive sperm motility in rats by reducing oxidative stress and upregulating CLDN3 and SRD5A2 expressions].

Objective: To investigate the protective effect of long-term consumption of hydrogen-rich water (HRW) on the percentage of progressively motile sperm (PMS) in male rats. METHODS: Twenty normal healthy male SD rats were equally randomized into an HRW and a control group, the former given HRW (1.2 ppm) and the latter normal saline, both intragastrically at 2 ml/d for 9 months. Then, the bilateral epididymides of the rats were harvested for preparation of sperm suspension and detection of the percentage of PMS. The testis tissue was isolated for HE staining and determination of the expressions of the Ki67, CYBB, eNOS, CLDN3 and SRD5A2 proteins using the streptavidin-peroxidase (SP) immunohistochemical method. RESULTS: The percentage of PMS was significantly higher in the HRW than in the control group (ï¼»64.3 ± 4.7ï¼½% vs ï¼»55.3 ± 9.5ï¼½%, P < 0.05), and so was the expression of Ki67 in the testicular tissue (P < 0.01). Compared with the controls, the rats in the HRW group showed markedly decreased oxidative stress-related index CYBB (P < 0.01), increased eNOS level (P < 0.01), and upregulated expressions of sperm development-related proteins CLDN3 and SRD5A2 (P < 0.01 and P < 0.05). CONCLUSIONS: Hydrogen not only regulates the expressions of some oxidative stress-related indicators, but also increases the expressions of the molecules promoting sperm maturation and motility, which provides a theoretical basis and experimental support for the application and studies of hydrogen in asthenospermia.

Exploring prognostic indicators in the pathological images of hepatocellular carcinoma based on deep learning.

OBJECTIVE: Tumour pathology contains rich information, including tissue structure and cell morphology, that reflects disease progression and patient survival. However, phenotypic information is subtle and complex, making the discovery of prognostic indicators from pathological images challenging. DESIGN: An interpretable, weakly supervised deep learning framework incorporating prior knowledge was proposed to analyse hepatocellular carcinoma (HCC) and explore new prognostic phenotypes on pathological whole-slide images (WSIs) from the Zhongshan cohort of 1125 HCC patients (2451 WSIs) and TCGA cohort of 320 HCC patients (320 WSIs). A 'tumour risk score (TRS)' was established to evaluate patient outcomes, and then risk activation mapping (RAM) was applied to visualise the pathological phenotypes of TRS. The multi-omics data of The Cancer Genome Atlas(TCGA) HCC were used to assess the potential pathogenesis underlying TRS. RESULTS: Survival analysis revealed that TRS was an independent prognosticator in both the Zhongshan cohort (p<0.0001) and TCGA cohort (p=0.0003). The predictive ability of TRS was superior to and independent of clinical staging systems, and TRS could evenly stratify patients into up to five groups with significantly different prognoses. Notably, sinusoidal capillarisation, prominent nucleoli and karyotheca, the nucleus/cytoplasm ratio and infiltrating inflammatory cells were identified as the main underlying features of TRS. The multi-omics data of TCGA HCC hint at the relevance of TRS to tumour immune infiltration and genetic alterations such as the FAT3 and RYR2 mutations. CONCLUSION: Our deep learning framework is an effective and labour-saving method for decoding pathological images, providing a valuable means for HCC risk stratification and precise patient treatment.

Expression of group IIA phospholipase A2 is an independent predictor of favorable outcome for patients with gastric cancer.

Growing evidence suggests that phospholipase A2 (PLA2) plays a pivotal role in tumorigenesis in human gastrointestinal cancer. One of the well-studied isoforms of PLA2, group IIA PLA2 (PLA2G2A), appears to exert its protumorigenic or antitumorigenic effects in a tissue-specific manner. The present study was designed to determine the expression profile and prognostic value of PLA2G2A in gastric cancer in a large Chinese cohort. By using real-time polymerase chain reaction, the amount of PLA2G2A messenger RNA in 60 pairs of fresh gastric tumors and adjacent noncancerous mucosa was measured. The immunostaining of PLA2G2A in 866 gastric cancers with paired noncancerous tissues was assayed. No expression of PLA2G2A was found in normal gastric mucosa, and focal expression of PLA2G2A was noticed in intestinal metaplasia, whereas significantly increased expression of PLA2G2A was observed in the cytoplasm of gastric cancer cells. Furthermore, the extent of PLA2G2A expression was associated with tumor size (P < .001), tumor differentiation (P = .001), T class (P < .001), N class (P < .001), and TNM stage (P < .001) of gastric cancer. Multivariate analysis showed that PLA2G2A expression was an independent predictor of survival for patients with gastric cancer (P = .024). Expression of PLA2G2A seems to be protective for patients with gastric cancer (hazard ratio, 1.423; 95% confidence interval, 1.047-1.935), and it may be a target for achieving better treatment outcomes.

Reduced group IVA phospholipase A2 expression is associated with unfavorable outcome for patients with gastric cancer.

Arachidonic acid metabolic pathway has been implicated in the inflammation-associated tumorigenesis of gastrointestinal cancers. As the rate-limiting enzyme of arachidonic acid production, group IVA phospholipase A2 (PLA2G4A) is hypothesized to play a fundamental role in gastric tumorigenesis as well as cyclooxygenase-2 (COX-2). However, little is known about the expression and role of PLA2G4A in gastric cancer, and the association of PLA2G4A with COX-2 remains to be elucidated. In this study, the mRNA expression of PLA2G4A and COX-2 in 60 pairs of fresh gastric tumors and corresponding adjacent non-cancerous mucosa was detected by using real-time quantitative PCR and the immunostaining of the both proteins in paired samples from 866 gastric cancer patients were assessed by using immunohistochemistry method. The clinicopathological and the prognostic relevance of PLA2G4A and COX-2 expression were determined. The results revealed a significantly reduced expression of PLA2G4A in gastric tumors compared to in non-cancerous tissues, as opposite to the increased expression of COX-2. PLA2G4A was significantly associated with tumor size (P = 0.003), tumor grade (P < 0.001), intestinal type (P = 0.003), T classification (P < 0.001), N classification (P < 0.001), and thereby TNM stage (P < 0.001). PLA2G4A and COX-2 expression were both identified as independent prognostic factors in multivariate Cox model analysis (P = 0.024 for PLA2G4A and P < 0.001 for COX-2). Moreover, the reduced PLA2G4A and increased COX-2 expression was both associated with unfavorable survival for patients with gastric cancer. PLA2G4A might serve as a promising target for future therapeutic approaches to gastric cancer combined with COX-2 inhibitors.

Expression profile and prognostic role of sex hormone receptors in gastric cancer.

BACKGROUND: Increasing interest has been devoted to the expression and possible role of sex hormone receptors in gastric cancer, but most of these findings are controversial. In the present study, the expression profile of sex hormone receptors in gastric cancer and their clinicopathological and prognostic value were determined in a large Chinese cohort. METHODS: The mRNA and protein expression of estrogen receptor alpha (ERα), estrogen receptor beta (ERß), progesterone receptor (PR), and androgen receptor (AR) in primary gastric tumors and corresponding adjacent normal tissues from 60 and 866 Chinese gastric cancer patients was detected by real-time quantitative PCR and immunohistochemistry method, respectively. The expression profile of the four receptors was compared and their associations with clinicopathological characteristics were assessed by using Chi-square test. The prognostic value of the four receptors in gastric cancer was evaluated by using univariate and multivariate Cox regression analysis. RESULTS: The presence of ERα, ERß, PR, and AR in both gastric tumors and normal tissues was confirmed but their expression levels were extremely low except for the predominance of ERß. The four receptors were expressed independently and showed a decreased expression pattern in gastric tumors compared to adjacent normal tissues. The positive expression of the four receptors all correlated with high tumor grade and intestinal type, and ERα and AR were also associated with early TNM stage and thereby a favorable outcome. However, ERα and AR were not independent prognostic factors for gastric cancer when multivariate survival analysis was performed. CONCLUSIONS: Our findings indicate that the sex hormone receptors may be partly involved in gastric carcinogenesis but their clinicopathological and prognostic significance in gastric cancer appears to be limited.

Interleukin-8, a promising predictor for prognosis of pancreatic cancer.

AIM: To investigate the value of interleukin-8 (IL-8), a pro-inflammatory chemokine, in predicting the prognosis of pancreatic cancer. METHODS: Expression of IL-8 and its receptor CXCR1 was assessed by immunohistochemistry in pancreatic cancer and chronic pancreatitis samples. Enzyme-linked immunosorbent assay was used to detect the serum IL-8 levels in pancreatic cancer patients. Human pancreatic cancer tissues were heterotopically transplanted to the immune-deficiency mice to evaluate the effect of serum IL-8 on the tumorigenesis of the cancer samples. RESULTS: IL-8 and CXCR1 proteins were both over-expressed in pancreatic adenocarcinoma samples (55.6% and 65.4%, respectively) compared with the matched para-cancer tissues (25.9% and 12.3%, P < 0.01), or chronic pancreatitis (0% and 25%, P < 0.05). Serum IL-8 levels in pancreatic cancer patients (271.1 ± 187.7 ng/mL) were higher than in other digestive system tumors, such as gastric cancer (41.77 ± 9.11 ng/mL, P = 0.025), colorectal carcinoma (78.72 ± 80.60 ng/mL, P = 0.032) and hepatocellular carcinoma (59.60 ± 19.80 ng/mL, P = 0.016). In vivo tumorigenesis analysis further proved that tumor tissues from patients with higher serum IL-8 levels grew faster than those with lower IL-8 levels. CONCLUSION: IL-8 can be a fine serum marker for predicting the prognosis pancreatic cancer.

The p300/CBP associated factor is frequently downregulated in intestinal-type gastric carcinoma and constitutes a biomarker for clinical outcome.

OBJECTIVES: To investigate the expression of P300/CBP-associated factor (PCAF) protein in intestinal type gastric cancer (ITGC); analyze the relationship between the expression of PCAF protein and the clinical pathological characteristics of patients; explore the effects of PCAF protein on biological behaviors of ITGC. RESULTS: The expression of PCAF was markedly down-regulated in GC cell lines and ITGC tissues. PCAF was able to suppress tumorigenicity of GC cells both in vitro and in vivo, including colony formation in soft agar and tumor formation in nude mice. PCAF could also inhibit GC cells entering S phase from G1 phase. Statistical analysis displayed a significant correlation in PCAF expression with the gastric wall invasion, tumor size, TNM stage, p21, pRb (P<0.001) and PCNA (P<0.01) in ITGC specimens. A reduced PCAF protein expression correlated significantly with a mutant type p53 protein expression (P<0.01). Univariate analysis indicated that the patients demonstrating the high-PCAF/wild type p53 expression have a significantly (P<0.0001) better overall survival (OS), while multivariate analysis indicated that the location, lymph node metastasis, PCAF/p53 (P<0.0001), gastric wall invasion (P=0.001) and PCNA (P=0.018) are independently significant prognostic factors for OS. METHODS: Immunohistochemistry was performed to evaluate the expression of PCAF in a large subset containing 406 ITGC samples. Eukaryotic expression plasmid pcDNA3.1/PCAF was constructed and transfected into the human gastric cancer cell line SGC-7901 and protein expression was detected by Western blot. The proliferation and cell cycle of gastric cancer cells were evaluated by MTT assay and flow cytometry. Tumor growth in nude mice was used to access the tumorigenicity of gastric cancer cells. Apoptosis cells were detected by TUNEL staining. CONCLUSION: Reduced expression of PCAF plays an important role in the development of ITGC and correlates with a poor clinical outcome.

Overexpression of Grb2/HER2 signaling in Chinese gastric cancer: their relationship with clinicopathological parameters and prognostic significance.

PURPOSE: Growth factor receptor-bound 2 (Grb2)-mediated HER2 signaling is thought to play a critical role in gastric cancer development, progression and metastasis. However, little is known about their expression in gastric cancer. In this study, we try to explore their relationship with clinicopathological parameters and prognostic significance in gastric cancer patients. MATERIALS AND METHODS: We examined the expression of Grb2 and HER2 in normal gastric mucosa, primary gastric cancers, and lymph node metastases using immunohistochemical analysis of tissue microarrays containing specimens obtained from 1,143 patients with gastric cancer. RESULTS: Grb2 was overexpressed in 48% (553/1,143) of primary tumors and 59% (155/262) of lymph node metastases. We observed significant differences in Grb2 expression between the primary tumors and the lymph node metastases (P < 0.01). Also, HER2 was overexpressed in 28% (321/1,143) of the primary tumors and 30% (79/262) of the lymph node metastases. Overexpression of Grb2 and Her2 was associated with age (>60 years), tumor location (cardia of stomach), adenocarcinoma, and high/moderate differentiation. A significant relationship was found between Grb2 and HER2 expression using Chi-Square Tests and Spearman Correlation. Overexpression of Grb2 correlated significantly with poor survival rates in both univariate and multivariate analysis. CONCLUSIONS: Our data demonstrated a progressive amplification of Grb2 and HER2 expression in gastric carcinogenesis, suggesting the importance of Grb2 and HER2 as positive biomarkers for gastric cancer development and progression.

Prognostic value of the ratio of metastatic lymph nodes in gastric cancer: an analysis based on a Chinese population.

BACKGROUND AND OBJECTIVES: To determine the prognostic value of the ratio of metastatic lymph nodes (RML) for gastric cancer and compare it to the prognostic value of the number-based pN classification. METHODS: The survival of 513 patients who underwent curative resection between 2000 and 2005 was retrieved. The prognostic value of two factors for nodal status: RML classification (RML0, 0%; RML1, < or =30%; RML2, < or =50%; RML3, >50%) and pN classification (6th TNM system), was analyzed. RESULTS: Both RML and pN classifications were independent prognostic factors when considered separately in multivariate analysis (P-values < 0.05). Moreover, the proportion of explained variation (PEV) analysis showed that each classification had more prognostic value than other prognostic factors in two models respectively (P-values < 0.05). The D-measure for prognostic separation was 1.563 versus 1.383 for RML versus pN. Bootstrap results for the difference of D-measures did not show a significant difference between RML and pN in terms of prognostic power (95% CI, -0.102 to 0.175). CONCLUSIONS: RML is an independent prognostic factor for gastric cancer. However, no significant evidence is found to support the hypothesis that RML classification carries more prognostic value than pN classification.

New insight into the key proteins and pathways involved in the metastasis of colorectal carcinoma.

Metastasis-associated genomic alterations have been recognized to play a critical role in tumor metastasis. Primary and metastatic tumor cells in mice and tumors in a patient were studied by cDNA array analysis. Selected genes were determined by RT-PCR and immunohistochemistry. Pathways on changed genes were statistically analyzed. The function of Grb2 was determined by in vitro wound assay. Nodal metastatic cells had a stronger ability of growth and metastasis than primary tumor cells. A total of 376 genes showed a different expression between primary and metastatic cells. The expression of Grb2 and genes in the Grb2-mediated pathways was significantly elevated in the metastases. Elevated levels of Grb2 expression in metastases were related to the distant metastasis of colorectal carcinoma. Blocking the Grb2-SH2 domain signaling transduction inhibited cell motility. Metastasis-associated genes identified by cDNA and tissue microarrays provide potentially valuable information on the metastasis of colorectal tumors. Overexpression of Grb2 may contribute to tumor growth, invasiveness and metastasis.

Tumor size: a non-neglectable independent prognostic factor for gastric cancer.

BACKGROUND AND OBJECTIVES: The role of tumor size should not be neglected in the management of gastric cancer and its prognostic value needs precise reevaluation. METHODS: The survival data of 513 patients who underwent radical resection between 2000 and 2005 were collected retrospectively. Tumor size, measured as the maximum diameter of tumor, was categorized into four subgroups (< or =2, < or =3, < or =5, >5 cm) using the method of minimizing the estimated average expected distance (AED) objective function. The prognostic value of tumor size and the correlation between tumor size and other clinicopathologic factors were investigated. RESULTS: In multivariate analysis, status of lymph nodes (P < 0.001), depth of invasion (P < 0.001), type of resection (P = 0.004), age (P = 0.008), tumor size (P = 0.014), and perioperative blood transfusion (P = 0.034) were confirmed as independent prognostic predictors for patients with gastric cancer. Log linear model suggested that the status of lymph nodes and the depth of invasion associated with the tumor size significantly. CONCLUSIONS: The tumor size is a non-neglectable independent prognostic factor for patients with gastric cancer and more attention should be paid to its role in the management of gastric cancer.

[Expressions of nm23, P53 and S100A4 proteins and their relationships with metastasis potential in gastric carcinoma].

OBJECTIVE: To investigate the expression levels of nm23, P53, and S100A4 in gastric carcinoma and their relationships with clinicopathologic parameters and metastasis potential. METHODS: Pathological specimens from gastric carcinoma,matched para-tumor tissues, metastatic lymph node and distant metastatic tissues were examined for the expression levels of nm23, P53, and S100A4 proteins by tissue microarray technique and immunohistochemistry. RESULTS: The expression levels of P53 and S100A4 were upregulated (P< 0.01), while the expression of nm23 downregulated (P< 0.05) in gastric carcinoma compared with non-tumor tissues. S100A4 expression was significantly higher in distant metastatic tissues, while nm23 lower in metastatic lymph nodes than those in cancer tissues. Upregulating expression levels of nm23, P53, and S100A4 were significantly correlated with some malignant behaviour of gastric cancer. The expression rates of nm23+/P53+, P53+/S100A4+, and nm23+/S100A4+ immunohistochemical phenotypes were 48/74 (64.9%), 50/74 (67.6%), and 39/74 (52.7%). P53+/S100A4+, nm23+/S100A4+, and nm23+/P53+/S100A4+ phenotypes were associated with high metastasis potential of gastric cancer. CONCLUSIONS: Alteration of nm23, P53, and S100A4 expression may contribute to the development of gastric carcinoma. Nm23 and S100A4 proteins play a critical role in tumor metastasis. Co-detection of the expression of P53, nm23, and/or S100A4 can be used to evaluate high metastasis potential of gastric cancer.

Effects of hepatitis B virus on p53 expression in hepatoma cell line SMMU-7721.

AIM: To investigate the contribution of HBV in the development of hepatocarcinoma by examining the effects of HBV on p53 function in SMMU-7721 cell line. METHODS: Plasmid pCMVp53 was transfected or cotransfected with pCMVHBVa (wild-type HBV) or PCMVHBVb (mutation type HBV) into the hepatoma cell line SMMU-7721 by lipofectamine. Apoptosis cells were labeled with annexin V-FITC and confirmed by flow cytometry. Reporter plasmid PG13-CAT or p21-luc was cotransfected, respectively, into each group to determine the transactivation activity of p53 and its effect on p21 promoter. Western blot was performed to observe p53 expression in hepatoma cell line of each group. RESULTS: The group transfected with pCMVp53 alone exhibited higher luciferase activity and higher apoptosis rate, otherwise, the p53 expression and reporter activity of PG13-CAT or P21-luc as well as cell apoptosis rate were obviously higher in the group cotransfected of pCMVp53 with pCMVHBVa, but not in the other cotransfected group. CONCLUSION: Transient transfection of HBV into the SMMU-7721 cell line can enhance p53 expression and its effects on development of hepatocarcinoma.

[Mucinous noncystic (colloid) adenocarcinoma of the pancreas].

OBJECTIVE: To determine the clinicopathologic characteristics and the relationship between related gene expression and pathobiologic behavior of pancreatic mucinous noncystic adenocarcinoma. METHODS: Among the 249 pancreatic carcinoma cases from the department files, 6 tumors were identified to meet the pathologic criteria of colloid carcinoma. Envision immunohistochemical staining technique was used to detect expression of p21(ras), p21(WAF1), p16, p33(ING1), p53, ATM, MDM2, PCNA, Cyclins (D1, D3, A, B and E). Intra- and extra- cellular mucin production were determined by AB-PAS staining. Clinically, all of 6 cases were followed to June, 2003. RESULTS: In all 6 cases, the tumors were located in the head of the pancreas and all displayed similar microscopic findings. Duodenal invasion was seen in 4 cases and perineural invasion was seen in 1 case. Tumor metastasis in the liver was seen in 2 cases and in the regional lymph nodes in 2 cases. Positive immunostaining was seen in 5 cases with p21(ras), 3 cases with p21(WAF1), 1 case with p16, 4 cases with p33(ING1), 2 cases with p53, 3 cases with ATM, 3 cases with MDM2, 6 cases with PCNA, 3 cases with cyclinA, 3 cases with cyclinD1, 4 cases with cyclinD3, 4 cases with cyclinB and 6 cases with cyclinE. Both extracellular and intracellular mucin was strongly positive for AB-PAS staining. Clinical follow-up found that 2 patients died of their tumors at 14 and 20 months. Three patients were alive after 28, 49 and 87 months of follow-up. One case were lost contact. CONCLUSIONS: Pancreatic mucinous noncystic adenocarcinoma has distinct morphologic features and biologic behavior. Multiple gene products including many cyclins may be involved in the pathogenesis of pancreatic colloid carcinoma. The tumor has an aggressive behavior with a high frequency of invasion and metastases, though the prognosis could be better than that of ordinary ductal adenocarcinoma of pancreas.

[Influence of Smad4-independent pathway of transforming growth factor beta1 on the biological activity of pancreatic cancer cells].

OBJECTIVE: To study effects of the expression of transforming growth factor (TGF)-beta1 on the growth of Smad4-null pancreatic cancer cells. METHODS: TGF-beta1 eukaryotic expression vector was transfected into pancreatic cancer cell line BxPC3. Effects of the expressison of TGF-beta1 was studied by growth curve analysis and flow cytometry. Cell motility was monitored by wound-healing assay. Western blot was used to estimate the expression level of p21(WAF/CLIP1), a cyclin-dependent kinase inhibitor. RESULTS: Transfection of TGF-beta1 changed the morphology of BxPC3 into spindle shaped cells. The growth rate of BxPC3 began to decrease after the fourth day of TGF-beta1 transfection, compared with the control groups. Flow cytometry showed that the percentages of cells in the S phase were (27.53 +/- 0.02)%, (26.32 +/- 0.01)% and (17.01 +/- 0.03)% in naïve BxPC3, vector-control group and TGF-beta1 transfection group respectively. Lesser cells entered the S phase after TGF-beta1 transfection (P < 0.01), but no difference was seen between the BxPC3 and vector groups (P > 0.05). The expression of p21(WAF/CLIP1) increased upon the expression of TGF-beta1. CONCLUSION: The Smad4-independent pathway of TGF-beta1 not only induces epithelial-mesenchymal transition in pancreatic cancer BxPC3, but also inhibits its growth through the up-regulation of p21(WAF/CLIP1).

[Expression and clinical significance of P53 pathway-associated proteins in pancreatic carcinoma].

BACKGROUND & OBJECTIVE: P53 pathway plays a critical role in carcinogenesis of pancreatic carcinoma. However, its trigger and function mechanisms have seldom been reported. This study was to investigate the expression and clinical significance of P53 pathway-related proteins ATM, P53, Mdm2, and P21(WAF/CIP1) in pancreatic carcinoma. METHODS: The expression of ATM, P53, Mdm2, and P21(WAF/CIP1) proteins in 167 specimens of pancreatic carcinoma and 112 specimens of non-cancer pancreatic tissues was detected by tissue microarray and immunohistochemistry. RESULTS: The positive rates of P53 and Mdm2 were higher in pancreatic carcinoma than in non-tumor pancreatic tissues (57.5% vs. 6.3%, 64.1% vs. 5.4%, P < 0.01), while the positive rates of ATM and P21(WAF/CIP1) were lower in pancreatic carcinoma than in non-tumor pancreatic tissues (67.7% vs. 82.1%, 39.5% vs. 71.4%, P < 0.05). ATM expression in pancreatic carcinoma was related to patients' age (P < 0.05). P53 expression was related to tumor differentiation, lymph node metastasis, and nerve involvement (P < 0.05). Mdm2 expression was related to tumor differentiation (P < 0.05). P21(WAF/CIP1) expression was related to patients' age and nerve involvement (P < 0.05). There were statistical correlations between these 4 proteins (P < 0.05). CONCLUSIONS: Overexpression of P53 and Mdm2 and loss of ATM and P21(WAF/CIP1) expression may contribute to the tumorigenesis and development of pancreatic carcinoma. The 4 proteins may affect cell transformation and tumorigenesis through ATM-Mdm2-P53-P21(WAF/CIP1) pathway. Co-detection of P53 and Mdm2 can be used to evaluate the differentiation of pancreatic carcinoma.

Genetic alterations and reduced expression of tumor suppressor p33(ING1b) in human exocrine pancreatic carcinoma.

AIM: To detect the expression of p33(ING1b) protein and the change of p33(ING1b) gene in pancreatic carcinoma and to evaluate the significance of p33(ING1b) in pancreatic cell carcinogenesis. METHODS: Pathological specimens from pancreatic carcinoma and matched non-tumor pancreatic tissues were examined for p33(ING1b) expression and mutation by immunohistochemistry, polymerase chain reaction single-strand conformation polymorphisms (PCR-SSCP) and loss of heterozygosity (LOH). RESULTS: The rate of p33(ING1b) protein expression was 85% (34/40). A single germline missense mutation was detected in 1 of 40 tumors located at codon 215:TGC-TCC (Cys-Ser). Fourteen (60.9%) of 23 tumor samples showed LOH in all of the informative markers tested, but no mutation was detected in these tumors and only two of the informative tumors lacked expressions of p33(ING1b) protein. CONCLUSION: Mutation and loss of expression are not the main reasons for the disfunction of p33(ING1b) in pancreatic carcinoma, an abnormality at the level of chromosome and/or transcription may inhibit their normal functions, potentially contributing to pancreatic cell carcinogenesis.

[Interaction effect of p53 with HBV in hepatoma cell line SMMC-7721].

OBJECTIVES: To study the interaction of hepatitis virus B (HBV) and tumor suppressor p53. METHODS: Plasmid pCMVp53 was transfected or cotransfected with pCMVHBVa (wild type HBV) or PCMVHBVb (mutant type HBV) into the hepatoma cell line SMMC-7721 by lipofectamine. Apoptosis cells were labeled by annexin V-FITC and confirmed by flow cytometry. Reporter plasmids PG13-CAT or p21-luc were cotransfected respectively in each group to indicate transactivation activity of p53 and it's effect on p21 promoter. Western blot was performed to observe p53 expression in each group. RESULTS: The group transfected by pCMVp53 alone exhibit higher luciferase activity and higher apoptosis rate, otherwise, p53 expression, enzyme activity of PG13-CAT or p21- luc and cell apoptosis rate were much higher in the group cotransfected by pCMVp53 and pCMVHBVa, but not in the other cotransfected group; HBV replication was enhanced in p53 cotransfected group. CONCLUSION: p53 expression and effects could be enhanced by HBV and p53 had positive regulation effect on HBV replication.