Prognostic significance of cytoplasmic p53 overexpression in colorectal cancer. An immunohistochemical analysis

Early reconstruction of the thumb carpometacarpal (CMC) joint after traumatic dislocation, when instability is present, may decrease the incidence of recurrent instability and post-traumatic joint degeneration. We report two retrospective cohort groups of patients who had sustained a traumatic thumb CMC joint dislocation. The first 8 patients, group A, were treated with closed reduction and pinning. Because the results were unsatisfactory with 4 patients, requiring revision surgery for recurrent instability in 3 and degenerative arthritis in 1, the treatment plan was changed to open reduction with a flexor carpi radialis weave, group B. The 9 patients in group B underwent early (an average of 7 days after injury) ligamentous reconstruction to decrease the incidence of joint damage from recurrent instability and improve long-term functional results. For patients in group B with a minimum follow-up period of 2 years, pain was not a major problem, and range of motion and grip strength were essentially preserved. The functional variables affected most in both groups were thumb abduction, which was decreased by 10%, and pinch strength, which was decreased by 13%, in group B, as compared to 20% and 19%, respectively, for the patients in group A. Radiographically, the joint space was slightly narrowed (Eaton stage II) in 3 cases in group B; however, these were asymptomatic. In group A, 5 patients demonstrated degenerative changes of the CMC joint (3 Eaton stage II, 2 stage III), and 3 patients were symptomatic after treatment.     

p53 nuclear protein overexpression in colorectal cancer: a dominant predictor of survival in patients with advanced hepatic metastases

PURPOSE: To determine whether p53 protein expression is similar within primary colorectal cancer (CRC) and synchronous regional and distant metastases and to assess whether p53 nuclear protein expression could predict outcome in patients with synchronous unresectable liver metastases treated by hepatic artery infusional (HAI) chemotherapy. MATERIALS AND METHODS: Paraffin sections from tumor and corresponding normal mucosa representative of 50 consecutive advanced CRC cases were examined for p53 nuclear protein expression by immunohistochemistry using the monoclonal antibody PAb 1801. Patterns of p53 nuclear expression were correlated with standard clinicopathologic variables and outcome, including response to HAI and survival. In a subset analysis, the pattern of nuclear p53 immunoreactivity was compared between primary CRC and lymph node and liver metastases. RESULTS: Positive nuclear immunoreactivity for p53 protein was found in 72% of cases. The pattern of p53 protein expression in lymph node and liver metastases was identical to that of the primary tumor. The median survival time was 21.0 months in patients with p53-positive tumors and 53.2 months in patients with p53-negative tumors (Wilcoxon test P = .038). Two-year survival rates were 41.7% and 78.6%, respectively (P < .01). No significant difference was found in the response rates to HAI chemotherapy between the two groups. By multivariate analysis, p53 protein status was the single best predictor of survival, with a relative risk of 6.312. CONCLUSION: Our results indicate that nuclear p53 protein status in primary CRC is similar to that in metastatic sites and may be the dominant predictor of survival in patients with advanced hepatic metastases.     

p53 and colorectal cancer

Mutations of the p53 gene have been found in 380 of the 768 tumors (49.5%) included in the eight largest published series of colorectal cancer. Most point mutations of p53 change the conformation of the gene, and by stabilizing it make it detectable by immunohistochemistry. However, studies using both tests for p53 mutations and immunohistochemical methods found that the results of these two approaches were concordant in only 68% of cases. Conflicting data have been reported regarding the prognostic significance of positive p53 staining. Presence of a mutation is generally believed to indicate a poor prognosis.     

Detection of protein p53 in the stool of patients with colorectal cancer

BACKGROUND AND AIMS: Mutations of TP53, a tumor suppressor gene, are found in 60% to 70% of colorectal cancers. These mutations usually induce an overexpression caused by modification of the p53 protein conformation. The aim of this study was to investigate whether stool specimens of patients with colorectal cancer contain increased amounts of p53 protein. METHODS: p53 protein was measured using a sandwich enzyme immunoassay in the stool specimens of 52 patients: 25 with colorectal cancer, 4 with colorectal adenomas and 23 apparently free of gastrointestinal disease. Results were expressed as pg/mg of total protein. The presence of fecal occult-blood was searched using Hemoccult II and Hemolex (an immunochemical assay for human hemoglobin). RESULTS: Median concentrations of stool p53 protein were 16.6 pg/mg (range: 0-591 pg/mg) in patients with colorectal cancers, 39.1 pg/mg (range: 5-72 pg/mg) in patients with adenomas and 5.9 pg/mg (range: 0-65 pg/mg) in control subjects. Resection of colorectal cancers caused a marked decrease of stool p53 protein concentrations. When the cut-off value for stool p53 protein was set at 60 pg/mg of fecal protein (concentrations over the 95th percentile), the positivity of the assay was independent of tumor size and Astler-Coller stage, but weakly associated with rectal location of cancer. The sensitivity of stool p53 protein for colorectal cancer was 44%, and the specificity was 96%. In contrast, the sensitivity of Hemoccult II and Hemolex tests was 48% and 44%, whereas their specificity was 91% and 96%, respectively. CONCLUSION: The detection of p53 protein is achievable in stool, but this assay is not more efficient than fecal occult blood tests for detection of colorectal cancer.     

p53 and prognosis in colorectal cancer

Treatment of rat liver arginase with N-bromosuccinimide results in modification of six tryptophan residues per enzyme molecule and is accompanied by loss of catalytic activity (E. Ber and G. Muzynska (1979) Acta Biochim. Pol. 26, 103-114). In order to probe the chemistry of N-bromosuccinimide inactivation and the role of tryptophan residues in catalysis, the two tryptophan residues of rat liver arginase, Trp122 and Trp164, have been separately mutated to phenylalanine using site-directed mutagenesis of the protein expressed in Escherichia coli. Both single Trp -> Phe mutant enzymes have kinetic parameters nearly identical to those for the wild-type enzyme. Treatment of native, wild-type, and each of the Trp -> Phe mutant enzymes with N-bromosuccinimide results in loss of absorbance at 280 nm and is accompanied by a loss of catalytic activity. However, treatment of the wild-type enzyme with N-bromosuccinimide in the presence of the arginase inhibitors NG-hydroxy-L-arginine or the combination of L-ornithine and borate protects against inactivation, even though tryptophan residues are modified. Treatment of the H101N and H126N mutant arginases with N-bromosuccinimide also results in loss of catalytic activity and modification of tryptophan residues. In contrast, the H141N mutant arginase is not inactivated by N-bromosuccinimide, indicating that His141 is the critical target for the N-bromosuccinimide inactivation of the enzyme.     

Comparison of p53 gene mutation and protein overexpression in colorectal carcinomas

Immunocytochemistry (ICC) has been used routinely to stain for p53 overexpression in a range of human tumours. The underlying assumption has been that positive staining indicates a mutation in the p53 coding sequence. Recently, however, discordancy has been observed and the accuracy of ICC as a marker of p53 gene mutation has been questioned. In this study of 109 colorectal adenocarcinomas, we compared ICC staining with p53 gene mutations detected by single-strand conformation polymorphism (SSCP) analysis. Concordancy between the two techniques was found in 69% of tumours. ICC-positive/SSCP-negative cases accounted for 20% of tumours and ICC-negative/SSCP-positive cases for the remaining 11%. These results caution against the assumption that p53 protein overexpression is always associated with a gene mutation. Epigenetic phenomena may account for a significant proportion of ICC-positive tumours.     

Increased serum p53 antibody levels indicate poor prognosis in patients with colorectal cancer

Serum p53 antibody levels were analysed using an enzyme-linked immunosorbent assay in serum samples obtained before surgery from 184 consecutive patients with primary colorectal cancer. Possible associations with tumour stage and tumour differentiation and the relation to patient survival time after a median follow-up of 6 years were studied. Analysis of serum p53 antibodies in the entire material demonstrated prognostic value in univariate analysis (P = 0.02); a finding that did not remain (P = 0.07) when the Dukes' stage was included in a multivariate analysis model. When the survival analysis was restricted to the potentially cured patients in Dukes' stages A-C, the serum p53 antibody levels retained independent prognostic value (P = 0.03). No clear association with tumour differentiation was found. We conclude that analysis of serum p53 antibodies may be of value for the identification of patients with different prognoses. This may be of relevance for selection of patients for adjuvant treatment.     

The significance of p53 autoantibodies in the serum of patients with breast cancer

Serum p53 autoantibodies were studied in 82 patients with Stage 1 or 2 breast cancer using an ELISA assay. Tissue expression of p53 in these patients was also examined. High levels of serum p53 autoantibodies were detected in 48% (39/82) patients, while 23% (19/82) were tissue positive. Patients with high serum p53 autoantibodies levels were not significantly different to those with low levels with respect to, tissue p53, tumour grade, size, stage or oestrogen receptor status. Tissue immunoreactivity for p53 was significantly associated with tumour grade and negative oestrogen receptor status. Patients in both groups were followed for a median of over five years but the presence of p53 autoantibodies in serum was not prognostic with respect to disease free interval or survival. In this study detection of p53 autoantibodies in serum does not correlate with any of the usual tumour related prognostic factors, nor does it correlate with clinical outcome.     

Clinicopathological characteristics of skipping lymph node metastases in patients with colorectal cancer

We evaluated the optic disc in 77 eyes of 77 normal volunteers using a scanning laser tomograph (Heidelberg Retina Tomograph: HRT, version 1.11). Particular attention was paid to age, refractive error, and disc size. The topographic parameters included: cup area, C/D area ratio, rim area, cup volume, rim volume, mean cup depth, maximum cup depth, cup shape measure, height variation contour, mean RNFL thickness, and RNFL cross section area. There was a significant decline in mean RNFL thickness and RNFL cross section area with increase in age (p < 0.05). The mean and maximum cup depths were significantly deeper in myopic eyes (p < 0.05). Large discs had large values of cup area, C/D area ratio, rim area, cup volume, mean cup depth, cup shape measure (p < 0.01), and maximum cup depth (p < 0.05). Large discs had small values of mean RNFL thickness and RNFL cross section area. Rim volume was independent of age, refractive error, or disc area.     

Stabilised p53 facilitates aneuploid clonal divergence in colorectal cancer

Mutations in the p53 tumour suppressor gene are amongst the most frequent genetic abnormalities acquired in tumours. Recent studies in vitro suggest that mutant p53 destabilises the genome and facilitates development of aneuploidy. Here, in a study of 83 colorectal carcinomas, we demonstrate that alterations in p53 (detected by immunocytochemical stabilisation) precede and apparently facilitate divergence of aneuploid sub-clones. Aneuploidy in these tumours (but not those with normal p53) is predominantly in the subtetraploid range, suggesting that endoreduplication is important in its origin. This association with a specific phase of carcinoma progression is not shared by other commonly acquired genetic abnormalities in these tumours. These observations highlight the critical role of p53 in the regulation of abnormal chromosome replication and afford an explanation for the association between p53 abnormalities, aneuploidy and biological aggression in cancer.     

Ki-ras mutation and p53 overexpression predict the clinical behavior of colorectal cancer: a Southwest Oncology Group study

We assessed Ki-ras mutations by single-strand conformation polymorphism followed by DNA sequencing, p53 expression by immunohistochemistry, ploidy status, and S-phase fraction in 66 stage II and 163 stage III colon cancer patients enrolled on a randomized trial of surgery followed by observation or adjuvant levamisole or 5-fluorouracil (5FU) plus levamisole (Intergroup Trial 0035) to see whether these factors were independently associated with survival or with differential effects of adjuvant therapy. A Cox proportional hazards survival model was used to describe marker effects and therapy by marker interactions, with adjustment for the clinical covariates affecting survival. A Bonferroni adjustment was used to account for multiple testing. Mutation of the Ki-ras gene was found in 41% of the cancers and was associated with a poor prognosis in stage II but not stage III. In stage II, 7-year survival was 86% versus 58% in those with wild type versus Ki-ras mutations. After adjustment for treatment and clinical variables, the hazard ratio (HR) for death was 4.5; 95% confidence interval (CI), 1.7-12.1 (P = 0.012). p53 overexpression was found in 63% of cancers and was associated with a favorable survival in stage III but not stage II. Seven-year survival in stage III was 56% with p53 overexpression versus 43% with no p53 expression (HR, 2.2; 95% CI, 1.3-3.6; P = 0.012). Aneuploidy was more common in stage III than in stage II (66 versus 47%; P = 0.009) but was not independently related to survival in either group. The proliferative rate was greater in aneuploid than in diploid cancers but was not related to survival. There was no benefit of adjuvant therapy in stage II nor in any of the stage II subgroups defined by mutational status. In stage III, adjuvant therapy with 5FU plus levamisole improved 7-year survival in patients with wild-type Ki-ras (76 versus 44%; HR, 0.4; 95% CI, 0.2-0.8) and in those without p53 overexpression (64 versus 26%; HR, 0.3; 95% CI, 0.1-0.7). Adjuvant therapy did not benefit those with Ki-ras mutations or p53 overexpression. The effects of adjuvant therapy did not differ according to ploidy status or proliferative rate. Ki-ras mutation is a significant risk factor for death in stage II, and the absence of p53 expression is a significant risk factor for death in stage III colon cancer after adjustment for treatment and clinical covariates. Exploratory analyses suggest that patients with stage III colon cancer with wild-type Ki-ras or no p53 expression benefit from adjuvant 5FU plus levamisole, whereas those with Ki-ras mutations or p53 overexpression do not. An independent study will be required to determine whether response to adjuvant therapy in colon cancer depends on mutational status.     

Detection of p53 protein overexpression and DNA ploidy analysis in colon cancer

BACKGROUND/AIMS: This study was designed to demonstrate the accumulation of the mutant p53 protein in human neoplasms. The correlation of flow cytometric DNA ploidy pattern with p53 expression using the immunoblotting technique was also investigated. METHODOLOGY: In this study, the occurrence of p53 overexpression was analyzed in 34 cases of adenocarcinoma of the colon by western immunoblotting technique, using an anti-human p53 monoclonal antibody (Do-7). The nuclear protein extract from human colon tumor specimens was immunoblotted relative to protein standards of known molecular weight. Flow cytometric analysis was used to study the DNA ploidy pattern of the tumor cells. RESULTS: Monoclonal antibody p53-Do 7 detected a single band of 53 KDa in 70.5% (24 of 34) of the tumor specimens examined. Whereas, no bands were detected in the normal colon mucosa. The relation between p53 overexpression and the clinicopathological variable (Dukes' staging) was studied and no significant difference in p53 overexpression between Dukes' stages B and C was found. Flow cytometric analysis revealed a higher incidence of DNA aneuploidy in 75% (15 of 20) of p53 positive cases compared with 64.3% (9 of 14) in the diploid tumors. CONCLUSION: The immunoblotting technique can successfully detect the mutant p53 and is therefore expected to provide valuable information on the role of p53 in the process of carcinogenesis.     

Gastric cancer with p53 overexpression has high potential for metastasising to lymph nodes

Overexpression of the tumour suppressor gene p53 was investigated immunohistochemically in 96 primary gastric carcinomas and 26 corresponding metastatic perigastric lymph nodes. Abnormalities in p53 expression were found in 52 (54%) of the 96 primary carcinomas. Tumours stained positively for p53 frequently metastasised to lymph nodes (the metastatic rate: 85%) compared to findings in those with negative p53 staining (64%, P < 0.05). Ninety-two percent (24/26) of the malignant cells in the lymph nodes stained positively for p53. When the DNA ploidy pattern of the tumour was determined by flow cytometry, the aneuploid tumours in p53 positive and negative groups accounted for 69% and 45%, respectively (P < 0.05). Proliferative activity of the tumour, as measured by Ki-67 labelling, was significantly higher (30.6 +/- 12.0%) in the p53 positive group than that (25.1 +/- 10.7%) in the p53 negative group (P < 0.05). Thus, gastric cancer with a mutant p53 has high proliferative activity and metastasis to lymph nodes will probably occur.     

Bcl-2 protein expression: association with p53 and prognosis in colorectal cancer

In myocardial SPECT perfusion imaging, reorientation algorithms from transaxial image planes are used to generate short- and long-axis views of myocardial tracer uptake. We performed phantom experiments with 201Tl to delineate how image reorientation affects the results of quantitative image analysis. METHODS: Thirty consecutive patient studies were analyzed to characterize the distribution of the angle of reorientation in a clinical setting. Short-axis SPECT images of a cardiac phantom with and without a 180 degrees cold-spot insert were reconstructed with three different backprojection filters (ramp, Metz and Butterworth) and reoriented through different angles ranging from 45 degrees to 89 degrees. Four interpolation algorithms were used to calculate from the transaxial images the pixel values of the reoriented images: (a) a simple interpolator that averages the pixel values of the eight neighboring pixels of the transaxial image; (b) a three-dimensional linear interpolator; (c) a hybrid interpolator that combines a two-dimensional linear in-plane with a one-dimensional cubic across-plane interpolation; and (d) a three-dimensional cubic convolution interpolator. Images were reoriented twice with opposite angles so that the original and the reoriented images could be directly compared. Circumferential profile analysis was applied to determine the root mean square error of corresponding profiles and the difference of the extent and the severity of perfusion defects. Single and multivariate analyses of variance (ANOVA) were used to compare the effects of the reorientation angle, the backprojection filter and the interpolation algorithm. RESULTS: In the clinical studies, the angle between the transaxial and reoriented images was 75 degrees +/- 10 degrees (s.d.). In 48 phantom experiments, multivariate ANOVA demonstrated that the backprojection filter and the interpolation algorithm significantly affect the circumferential profiles and the extent and severity of a perfusion defect (p < 0.05). In contrast, the angle of reorientation was not a significant factor (p = ns). By univariate analysis, the three-dimensional cubic interpolator was associated with significantly (p < 0.05) less error than the simple and three-dimensional linear algorithms. Relative computation times (simple interpolator = 100%) were 119% for the three-dimensional linear, 136% for the hybrid and 243% for the three-dimensional cubic interpolator. CONCLUSION: For quantitative analysis of myocardial SPECT perfusion images, a Metz filter for filtered backprojection in combination with a three-dimensional cubic convolution interpolation for image reorientation appears to offer improved accuracy.     

Molecular surgery for human colorectal cancer with tumor suppressor p53 gene transfer

Recent advances in molecular biology have demonstrated that multistep genetic alterations are involved in the carcinogenesis of human colorectal cancer and that alteration of the p53 gene by mutation, deletion, or rearrangement is a major factor in this process. Human gene therapy has become a reality with the development of effective techniques for delivering the gene to the target cells. The efficacy of gene therapy for various types of genetic disease now being evaluated in clinical trials. These findings led us to develop a novel gene therapeutic strategy for human colorectal cancer that could replace the abnormal p53 gene using a recombinant, replication-defective adenoviral vector (termed Adp53). Infection with Adp53 induced rapid apoptotic cell death in DLD-1 and LoVo human colorectal cancer cell lines differing in their p53 status. Treatment with cisplatin following infection with Adp53 significantly suppressed the growth of WiDr colorectal cancer cells compared to single treatments alone. Thus restoration of wild-type p53 function exhibited an antitumor effect by inducing apoptosis as well as by markedly enhancing the effect of common chemotherapeutic agents in human colorectal cancer cells. In addition, Adp53 infection was antiangiogenic in SW620 human colorectal cancer cells. The application of this technology to human cancer therapy is now in progress. The article reviews recent highlights in this rapidly evolving field.     

Prognostic significance of tumor markers in colorectal cancer patients: DNA index, S-phase fraction, p53 expression, and Ki-67 index

Risk of colorectal cancer recurrence has traditionally been determined by use of pathologic staging. However, it is apparent that subgroups of patients exist within tumor stages whose clinical behavior differs. This study was undertaken to identify tumor-associated factors that might be predictive of outcome in patients with intermediate stages who will benefit the most from postsurgical adjuvant therapy. Seventy patients with stage II and III colorectal cancer were assessed for DNA index, S-phase fraction, p53 expression, and Ki-67 index. Tumor recurrence was analyzed by means of nonparametric tests and Cox proportional hazard models incorporating standard clinical and pathologic criteria. Of the four prognostic markers evaluated, Ki-67 index was significantly associated with disease recurrence (P = 0.02), whereas DNA index, S-phase fraction, and p53 expression were not. After stratification by tumor stage, significant associations between Ki-67 index and disease recurrence were retained in stage II tumors (P = 0.01) but not in stage III tumors (P = 0.23). Cox proportional hazard regression analysis indicated that among stage II patients, those with a Ki-67 index >45% were associated with 6.5 times greater risk for disease recurrence than those with a Ki-67 index >/=45%. It was concluded that an elevated Ki- 67 index is associated with an increased risk of tumor recurrence in stage II colorectal cancer.     

P53突变蛋白表达对弥漫大B细胞淋巴瘤预后的预测作用

目的 探讨p53突变蛋白表达对弥漫大B细胞淋巴瘤(DLBCL)预后的预测作用,指导个体化治疗.方法 随机选择初治DLBCL患者62例,应用免疫组织化学方法检测p53突变蛋白和CD10、bcl_6、MUM1的表达,分析p53突变蛋白表达与患者临床特征、分子分型以及预后的关系.结果 48.4%(30/62)的患者表达p53突变蛋白.p53突变蛋白表达与初始治疗反应有关(x2=20.365,P=0.040),阳性组的完全缓解率为33.3%(10/30),阴性组为59.4%(19/21);与分子分型有关(x2=31.023,P=0.021),阳性组非生发中心型比例显著高于阴性组,分别为83.3%和56.2%;与其他临床特征无关.多因素生存分析显示p53突变蛋白表达是独立的预后预测因子,阳性组的无进展生存期和中位生存期均短于阴性组(x2=36.784,P=0.005和x2=35.276,P=0.006).结论 p53突变蛋白表达是DLBCL独立的不良预后因子,能够用来指导个体化治疗.     

p53 gene therapy in vivo of herpatocellular and liver metastatic colorectal cancer

Tumor suppressor genes such as p53 contribute to the oncogenic process via loss-of-function mechanisms such as genetic mutation or complex formation with other cellular or viral proteins. p53 is mutated in approximately 50% of human tumors and has an important role in the genesis or progression of both colorectal and hepatocellular cancers. Colorectal cancer is leading cause of cancer mortality in the United States, whereas hepatocellular cancer is the leading worldwide cause of cancer death; the liver is a primary site of morbidity in both diseases. Because systemic tumor suppressor gene therapy is currently not feasible, we have chosen to develop a regional form of such therapy directed at primary or metastatic liver neoplasms. Gene replacement therapy with p53 is a promising new strategy to treat advanced human cancers.     

p53 protein overexpression as a predictor of the response to chemotherapy in gastric cancer

This study was performed to evaluate p53 overexpression as a predictor of the response to chemotherapy of patients with gastric cancer. The subjects comprised 20 patients with Stage IV gastric cancer and three with locally recurrent lesions, all of whom were treated with 5-fluorouracil (5-FU) plus cisplatin (CDDP) for 4 weeks. Of the total 23 patients there were 10 responders; 2 showing complete response (CR) and 8, partial response (PR). Specimens obtained by endoscopic biopsy were immunohistochemically stained using anti-p53 protein and bcl-2 protein antibody. Of the 10 responders, 7 demonstrated negative p53 staining, and of the 13 nonresponders, 11 demonstrated positive p53 staining (P = 0.013). Tissue from 3 of the responders and 7 of the nonresponders that stained for bcl-2 were positive prior to chemotherapy; however, there was no association between bcl-2 staining and chemotherapeutic effect. In conclusion, immunohistochemical identification of p53 in pretreatment tissue may represent a useful predictor for chemotherapeutic outcome in patients with gastric cancer.