Circulating p53 antibodies, p53 gene mutational profile and product accumulation in esophageal squamous-cell carcinoma in India

Association of elevated autoantibody to high expression of GNAS in hepatocellular carcinoma

Purpose

This study was based on hepatocellular carcinoma (HCC) patients of early-stage to explore the diagnostic capability and possible production causes of anti-GNAS autoantibody.

Methods

We evaluated the frequency of anti-GNAS autoantibody in sera from patients with early-stage HCC by enzyme-linked immunosorbent assay (ELISA) and the expression of GNAS protein in early-stage HCC tissues by immunohistochemistry. Western blotting (WB) and real-time polymerase chain reaction (RT-PCR) were utilized to examine the expressions of GNAS protein and mRNA in cell lines. GEO and International Cancer Genome Consortium (ICGC) databases were inquired to explore mRNA expression and mutation of GNAS in HCC tissues.

Results

The positive rates of anti-GNAS autoantibody in HCC patients at clinical stage I (78.1 %) and clinical stage II (57.1 %) were all significantly higher than that in healthy control (20 %). There was also a significant difference in GNAS protein expression between HCC and its adjacent normal liver tissues. The results from WB and RT-PCR showed a significant difference at the mRNA level but no statistical difference at the protein level between HCC and normal liver cell lines. The difference in mRNA level between HCC and adjacent normal liver tissues was verified to be significant. Furthermore, the ICGC database demonstrated a 10.6 % mutation frequency for GNAS in HCC patients.

Conclusion

The coordination of elevated anti-GNAS autoantibody, high expression of GNAS in the mRNA and protein levels in HCC, and high frequency of GNAS mutation indicates that anti-GNAS autoantibody may be used as an early indicator of HCC.

Antibodies as biomarkers for cancer risk: a systematic review

Increasing evidence has linked the humoral immune response with the development of various cancers. Therefore, there is growing interest in investigating the predictive value of antibodies to assess overall and tissue site-specific cancer risk. Given the large amount of antibody types and the broad scope of the search (i.e. cancer risk), the primary aim of this systematic review was to present an overview of the most researched antibodies (i.e. immunoglobulin (Ig) isotypes (IgG, IgM, IgA, and IgE), tumour and self-antigen-reactive antibodies, infection-related antibodies) in relation to overall and site-specific cancer risk. We identified various antibody types that have been associated with the risk of cancer. While no significant associations were found for IgM serum levels, studies found an inconsistent association among IgE, IgA, and IgG serum levels in relation to cancer risk. When evaluating antibodies against infectious agents, most studies reported a positive link with specific cancers known to be associated with the specific agent recognized by serum antibodies (i.e. helicobacter pylori and gastric cancer, hepatitis B virus and hepatocellular carcinoma, and human papillomavirus and cervical cancer). Several reports identified autoantibodies, as single biomarkers (e.g. anti-p53, anti-MUC1, and anti-CA125) but especially in panels of multiple autoantibodies, to have potential as diagnostic biomarkers for specific cancer types. Overall, there is emerging evidence associating certain antibodies to cancer risk, especially immunoglobulin isotypes, tumour-associated antigen-specific, and self-reactive antibodies. Further experimental studies are necessary to assess the efficacy of specific antibodies as markers for the early diagnosis of cancer.

The TP53-Related Signature Predicts Immune Cell Infiltration, Therapeutic Response, and Prognosis in Patients With Esophageal Carcinoma

TP53 mutation (TP53^MUT) is one of the most common gene mutations and frequently occurs in many cancers, especially esophageal carcinoma (ESCA), and it correlates with clinical prognostic outcomes. Nevertheless, the mechanisms by which TP53^MUT regulates the correlation between ESCA and prognosis have not been sufficiently studied. Here, in the current research, we constructed a TP53^MUT-related signature to predict the prognosis of patients with esophageal cancer and successfully verified this model in patients in the TP53 mutant group, esophageal squamous cell carcinoma group, and adenocarcinoma group. The risk scores proved to be better independent prognostic factors than clinical features, and prognostic features were combined with other clinical features to establish a convincing nomogram to predict overall survival from 1 to 3 years. In addition, we further predicted the tumor immune cell infiltration, chemical drugs, and immunotherapy responses between the high-risk group and low risk group. Finally, the gene expression of the seven-gene signature (AP002478.1, BHLHA15, FFAR2, IGFBP1, KCTD8, PHYHD1, and SLC26A9) can provide personalized prognosis prediction and insights into new treatments.

Tumor-associated antigens and their antibodies in the screening, diagnosis, and monitoring of esophageal cancers

Despite the advances in the treatment and management, esophageal cancers continue to carry a dismal prognosis with an overall 5-year survival rate ranging from 15 to 25%. Delayed onset of symptoms and lack of effective screening methods and guidelines for diagnosis of the early disease contribute to the high mortality rate of esophageal cancers. Detection of esophageal cancer at their early stage is really a challenge for physicians including primary care physicians, gastroenterologists and oncologists. Although imaging, endoscopy and biopsy have been proved to be useful diagnostic tools for esophageal cancers, their diagnostic accuracy is unsatisfactory. In addition, expensive costs, invasiveness and special training operator have limited the clinical application of these tools. Recently, tumor-associated antigens (TAAs) and their antibodies have been reported to be potential markers in esophageal cancer screening, diagnosis, monitoring and prognostication. Because TAAs and their antibodies have the advantages of inexpensive cost, noninvasiveness and easy access, they have attracted much attention as an affordable option for early esophageal cancer diagnosis. In this review, we summarized the advances in TAAs and their antibodies in esophageal cancer screening, diagnosis, monitoring and prognostication.

Identification and Characterization of a New Platinum-Induced TP53 Mutation in MDAH Ovarian Cancer Cells

Platinum-based chemotherapy is the therapy of choice for epithelial ovarian cancer (EOC). Acquired resistance to platinum (PT) is a frequent event that leads to disease progression and predicts poor prognosis. To understand possible mechanisms underlying acquired PT-resistance, we have recently generated and characterized three PT-resistant isogenic EOC cell lines. Here, we more deeply characterize several PT-resistant clones derived from MDAH-2774 cells. We show that, in these cells, the increased PT resistance was accompanied by the presence of a subpopulation of multinucleated giant cells. This phenotype was likely due to an altered progression through the M phase of the cell cycle and accompanied by the deregulated expression of genes involved in M phase progression known to be target of mutant TP53. Interestingly, we found that PT-resistant MDAH cells acquired in the TP53 gene a novel secondary mutation (i.e., S185G) that accompanied the R273H typical of MDAH cells. The double p53^S185G/R273H mutant increases the resistance to PT in a TP53 null EOC cellular model. Overall, we show how the selective pressure of PT is able to induce additional mutation in an already mutant TP53 gene in EOC and how this event could contribute to the acquisition of novel cellular phenotypes.

Serum anti-TOPO48 autoantibody as a biomarker for early diagnosis and prognosis in patients with esophageal squamous cell carcinoma

BACKGROUND AND AIM

We previously reported a novel tumor associated antigen (TTA) with molecular weight around 48kDa that is a fragment derived from human DNA-topoiomerase I (TOP1). We termed the novel TAA as TOPO48 and termed autoantibody against the TAA as anti-TOPO48 autoantibody. The aim of this study is to further investigate the clinical applications of the autoantibody in patients with esophageal squamous cell carcinomas (ESCC).

METHODS

Serum levels of the anti-TOPO48 autoantibody in 112 ESCC patients, 112 age- and gender-matched healthy controls and 75 patients with esophageal benign tumors were determined by using a specific anti-TOPO48 autoantibody ELISA. Then, we statistically evaluated its clinical significance.

RESULTS

We found that serum anti-TOPO48 autoantibody levels in ESCC patients were significantly higher than that in healthy controls and benign tumor patients (P=0.001). The percentage of sera with a positive level of anti-TOPO48 autoantibody in early stages was significantly higher than that in advanced stages of the cancer patients when the maximum level of healthy control sera was taken as a cut-off value (P=0.001). The area under ROC curve was 0.863 (95% CI=0.797-0.928) for healthy controls vs. early stage ESCC. In addition, patients with positive anti-TOPO48 autoantibody had significantly higher survival rate and longer survival time than that with negative anti-TOPO48 autoantibody in cancer patients (P=0.038, 0.025 and 0.047 for all stages, early stage and advanced stage, respectively).

CONCLUSIONS

Our results suggest that anti-TOPO48 autoantibody may be a potentially useful biomarker for early diagnosis and prognosis of ESCC.

Potential diagnostic value of serum p53 antibody for detecting colorectal cancer: A meta-analysis

Numerous studies have assessed the diagnostic value of serum p53 (s-p53) antibody in patients with colorectal cancer (CRC); however, results remain controversial. The present study aimed to comprehensively and quantitatively summarize the potential diagnostic value of s-p53 antibody in CRC. The present study utilized databases, including PubMed and EmBase, systematically regarding s-p53 antibody diagnosis in CRC, accessed on and prior to 31 July 2016. The quality of all the included studies was assessed using quality assessment of studies of diagnostic accuracy (QUADAS). The result of pooled sensitivity, pooled specificity, positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were analyzed and compared with overall accuracy measures using diagnostic odds ratios (DORs) and area under the curve (AUC) analysis. Publication bias and heterogeneity were also assessed. A total of 11 trials that enrolled a combined 3,392 participants were included in the meta-analysis. Approximately 72.73% (8/11) of the included studies were of high quality (QUADAS score >7), and all were retrospective case-control studies. The pooled sensitivity was 0.19 [95% confidence interval (CI), 0.18–0.21] and pooled specificity was 0.93 (95% CI, 0.92–0.94). Results also demonstrated a PLR of 4.56 (95% CI, 3.27–6.34), NLR of 0.78 (95% CI, 0.71–0.85) and DOR of 6.70 (95% CI, 4.59–9.76). The symmetrical summary receiver operating characteristic curve was 0.73. Furthermore, no evidence of publication bias or heterogeneity was observed in the meta-analysis. Meta-analysis data indicated that s-p53 antibody possesses potential diagnostic value for CRC. However, discrimination power was somewhat limited due to the low sensitivity.

Peritherapeutic Serum p53 Antibody Titers are Predictors of Survival in Patients with Esophageal Squamous Cell Carcinoma Undergoing Neoadjuvant Chemotherapy and Surgery

BACKGROUND

Although the preoperative serum level of p53 antibodies (s-p53-Abs) is reported to be a prognostic factor in esophageal squamous cell carcinoma (ESCC) patients, the clinical significance of post-therapeutic s-p53-Abs or the peritherapeutic changes in s-p53-Abs associated with the prognosis or treatment response of ESCC patients undergoing surgery following preoperative chemotherapy remains unclear.

METHODS

s-p53-Abs titers were peritherapeutically measured in 136 ESCC patients who underwent surgery following preoperative chemotherapy in our department from 2008 to 2014. Clinicopathological parameters, including the response to chemotherapy and the recurrence-free survival (RFS), were compared between groups classified by the levels of the s-p53-Ab titers and the peritherapeutic changes in the s-p53-Ab titers.

RESULTS

After curative surgery following preoperative chemotherapy, the s-p53-Ab titers increased in 15 patients (11.0%), remained unchanged in 81 patients (59.6%) and decreased in 40 patients (29.4%). The seropositive rate (cutoff value: 0.5 U/ml) of pre- and post-therapeutic s-p53-Abs were 36.0% (49/136) and 35.3% (48/136), respectively. Negative and positive seroconversion of s-p53-Abs was identified in 20.4% (10/49) and 10.3% (9/105) of patients, respectively. Both pre- and post-therapeutic seropositive s-p53-Ab titers significantly correlated with an unfavorable prognosis (p = 0.028, 0.002, respectively). Patients with a peritherapeutic increase in s-p53-Ab titers showed a shorter RFS compared with unchanged/decreased titers. Neither the s-p53-Ab titer at any time point nor its change was associated with the response to chemotherapy.

CONCLUSIONS

Both peritherapeutic s-p53-Ab titers and their changes were shown to be prognostic parameters in ESCC patients undergoing preoperative chemotherapy followed by surgery.

The Presence of Serum p53 Antibody Predicts the Pathological Tumor Response to Neoadjuvant Chemotherapy with Docetaxel, Cisplatin and Fluorouracil (DCF) in Esophageal Squamous Cell Carcinoma

BACKGROUND

Docetaxel, cisplatin and fluorouracil (DCF) is a candidate neoadjuvant chemotherapy (NAC) regimen for esophageal squamous cell carcinoma (ESCC). Although the efficacy and safety of DCF have been reported, the markers that predict the patient's response are still unknown. The aim of this study was to identify the predictive markers for a response to NAC with DCF in patients with ESCC.

METHODS

A total of 79 patients who received preoperative DCF followed by esophagectomy between August 2008 and December 2014 were enrolled in this study. All of the patients completed 2 preoperative courses of DCF. The clinical and pathological responses to DCF were investigated, and the associations between the pathological response, the clinicopathological factors and the prognosis were retrospectively analyzed.

RESULTS

Among the 79 patients, the pathological response to DCF (evaluated according to the Japanese Classification of Esophageal Cancer) was grade 3 (complete pathological response) in 7 patients (8.9 %), grade 2 in 13 patients (16.5 %), grade 1b in 8 patients (10.1 %) and grade 1a in 51 patients (64.6 %). A good pathological response (grade 2-3) was significantly associated with both favorable disease-free survival (P = 0.0051) and favorable cancer-specific survival (P = 0.0366). A multivariate analysis revealed that a good clinical response (HR 13.743, 95 % CI 2.455-76.917) and the presence of serum p53 antibody before treatment (HR 3.987, 95 % CI 1.103-14.416) were independent predictors of good pathological response.

CONCLUSIONS

The presence of serum p53 antibody can be used as a novel, noninvasive predictor of the pathological tumor response to NAC with DCF in ESCC patients.

Serum p53 antibody as a potential tumor marker in extrahepatic cholangiocarcinoma

PURPOSE

Only a few studies have evaluated the clinicopathological significance of the p53 protein expression and s-p53-Abs level in patients with cholangiocarcinoma. We therefore analyzed the clinicopathological and prognostic significance of s-p53-Abs in patients with extrahepatic cholangiocarcinoma.

METHODS

We prospectively evaluated s-p53-Abs levels before and after surgery in 61 patients with extrahepatic cholangiocarcinoma to determine the relationship between clinicopathological factors and the prognostic significance of s-p53-Abs.

RESULTS

Among a total of 61 primary extrahepatic cholangiocarcinoma cases, 23% were positive for s-p53-Abs. Combination of s-p53-Abs with the conventional serum markers carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) significantly increased the rate of positive extrahepatic cholangiocarcinoma cases (57% for CEA and/or CA19-9 vs. 75% for CEA and/or CA19-9 and/or s-p53-Abs, P = 0.035). There were no significant differences in clinicopathological factors between the p53-seropositive and p53-seronegative patients. An immunohistochemical analysis showed the presence of significant associations between the intensity (P = 0.003) and extent (P = 0.001) of p53 immunoreactivity and p53-seropositivitly. Although s-p53-Abs was not a significant prognostic factor for the survival in either univariate or multivariate analyses, p53 immunoreactivity was independently associated with a poor survival. Among patients positive for s-p53-Abs before surgery, the s-p53-Abs levels were reduced after surgery in most.

CONCLUSION

These findings suggested that s-p53-Abs might be associated with p53 immunoreactivity. In addition, s-p53-Abs may be useful for a diagnosis, but was not useful for predicting tumor recurrence or the survival. This study was registered as UMIN000014530.

Are p53 Antibodies a Diagnostic Indicator for Patients with Oral Squamous Cell Carcinoma? Systematic Review and Meta-Analysis

BACKGROUND

P53 has been reported to be involved with tumorigenesis and has also been implicated as a significant biomarker in oral squamous cell carcinoma(OSCC). However, the diagnostic value of p53 antibodies remains controversial; hence, we comprehensively and quantitatively assessed the potential in the present systematic review.

MATERIALS AND METHODS

A comprehensive search was performed using PubMed and Embase, up to October 31, 2014, without language restriction. Studies were assessed for quality using QUADAS (quality assessment of studies of diagnostic accuracy). The positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were pooled separately and compared with overall accuracy measures using diagnostic odds ratios (DORs) and symmetric summary receiver operating characteristic (SROC) curves.

RESULTS

Of 150 studies initially identified, 7 eligible regarding serum p53 antibodies met the inclusion criteria. Some 85.7% (6/7) were of relatively high quality (QUADAS score≥7). The summary estimates for quantitative analysis of serum p53 antibody in the diagnosis of squamous cell carcinoma were: PLR 2.06 [95% confidence interval (CI) : 1.35-3.15], NLR 0.85 (95%CI: 0.80- 0.90) and DOR 2.47 (95%CI: 1.49- 4.12).

CONCLUSIONS

This meta-analysis suggests that the use of s-p53-antibodies has potential diagnostic value with relatively high sensitivity and specificity for OSCC particularly with serum specimens for discrimination of OSCCs from healthy controls. However, its discrimination power is not perfect because of low sensitivity.

Nontoxic virus nanofibers improve the detection sensitivity for the anti-p53 antibody, a biomarker in cancer patients

The presence of anti-p53 antibody in serum is a biomarker for cancer. However, its high sensitivity detection is still an issue in cancer diagnosis. To tackle this challenge, we used fd phage, a human-safe bacteria-specific virus nanofiber that can be mass-produced by infecting host bacteria in an error-free manner, and genetically engineered it to display a peptide capable of recognizing and capturing anti-p53 antibody on its side wall. We employed the resultant phage nanofibers as a capture probe to develop a modified version of the enzyme-linked immunosorbent assay (ELISA) method, termed phage-ELISA. We compared it to the traditional ELISA method for the detection of anti-p53 antibody, p53-ELISA, which uses recombinant wild-type p53 protein to capture anti-p53 antibody. We applied phage-ELISA to detect anti-p53 antibody in an experimental group of 316 patients with various types of malignant tumors. We found that a detection rate of 17.7% (56 positive cases) was achieved by phage-ELISA, which was comparable to the detection rate of 20.6% for p53-ELISA (65 positive cases). However, when both phage and p53 were combined to form antibody-capturing probes for phage/p53-ELISA, a detection rate of 30.4% (96 positive cases) was achieved. Our work showed that owing to the combined capture of the anti-p53 antibody by both phage nanofibers and p53, the phage/p53-ELISA achieved the highest diagnostic accuracy and detection efficiency for the anti-p53 antibody in patients with various types of cancers. Our work suggests that a combination of nanofibers and antigens, both of which capture antibody, could lead to increased detection sensitivity, which is useful for applications in the life sciences, clinical medicine, and environmental sciences.

Diagnostic value of multiple tumor markers for patients with esophageal carcinoma

BACKGROUND

Various studies assessing the diagnostic value of serum tumor markers in patients with esophageal cancer remain controversial. This study aims to comprehensively and quantitatively summarize the potential diagnostic value of 5 serum tumour markers in esophageal cancer.

METHODS

We systematically searched PubMed, Embase, Chinese National Knowledge Infrastructure (CNKI) and Chinese Biomedical Database (CBM), through February 28, 2013, without language restriction. Studies were assessed for quality using QUADAS (quality assessment of studies of diagnostic accuracy). The positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were pooled separately and compared with overall accuracy measures using diagnostic odds ratios (DORs) and symmetric summary receiver operating characteristic (SROC) curves.

RESULTS

Of 4391 studies initially identified, 44 eligible studies including five tumor markers met the inclusion criteria for the meta-analysis, while meta-analysis could not be conducted for 12 other tumor markers. Approximately 79.55% (35/44) of the included studies were of relatively high quality (QUADAS score≥7). The summary estimates of the positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratio (DOR) for diagnosing EC were as follows: CEA, 5.94/0.76/9.26; Cyfra21-1, 12.110.59/22.27; p53 antibody, 6.71/0.75/9.60; SCC-Ag, 7.66/0.68/12.41; and VEGF-C, 0.74/0.37/8.12. The estimated summary receiver operating characteristic curves showed that the performance of all five tumor markers was reasonable.

CONCLUSIONS

The current evidence suggests that CEA, Cyfra21-1, p53, SCC-Ag and VEGF-C have a potential diagnostic value for esophageal carcinoma.

Serum autoantibodies in the early detection of esophageal cancer: a systematic review

Antibodies against tumor-associated antigens (TAAs) have been found in serum of patients with various types of cancers and may serve as biomarkers for early detection of esophageal cancer as well. This systematic review aims to give an overview about known autoantibodies and their diagnostic value in esophageal cancer. We conducted a systematic literature search in two databases to identify studies which performed serological testing for autoantibodies in esophageal cancer patients and controls. Data on study characteristics and results were extracted independently by two reviewers. Overall, 45 articles reporting the detection of 35 different autoantibodies met the inclusion criteria of this review. The most common antibody detection method was enzyme-linked immunosorbent assay (ELISA), and the most frequently assessed autoantibody was anti-p53, which was tested in 17 studies and for 15 studies of which a meta-analysis was conducted to comprehensively evaluate the diagnostic value. Most antibodies were assessed in only one study, and only few authors have evaluated the diagnostic value of combinations of multiple autoantibodies. For single autoantibodies, specificity was generally very high (median 98.3 %), but sensitivity was mostly rather low (median 26.7 %). For some autoantibody combinations, substantially higher sensitivity at reasonably high levels of specificity could be achieved. Development of extended and optimized multimarker panels of autoantibodies might be a promising approach for esophageal cancer early detection.

Detection of serum p53 antibodies from Chinese patients with papillary thyroid carcinoma using phage-SP-ELISA: correlation with clinical parameters

The goal of the present study was to investigate whether p53 antibodies (Abs) could be a relevant marker for papillary thyroid carcinoma (PTC). Three types of enzyme-linked immunosorbent assay (ELISA) methods were developed for the detection of p53 Abs, including p53-ELISA, phage-SS-ELISA, and phage-SP-ELISA. A total of 304 patients, including 117 cases with thyroid adenoma and 187 PTC patients, were enrolled in this study. Expression of p53 protein and mutation in BRAF gene were evaluated in paraffin-embedded tissue from 44 patients with PTC, in order to elucidate their correlations with the presence of p53 Abs. Compared with p53-ELISA and phage-SS-ELISA, phage-SP-ELISA presented the highest detection efficiency of p53 Abs in patients with PTC, and a combination of these three ELISA systems could make the detection of p53 Abs more sensitive than using each of the individual ELISA methods. Furthermore, p53 Abs was positively associated with clinical stage (P = 0.044), node metastasis (P = 0.010), and p53 protein accumulation (P = 0.019). These results indicate that serum p53 Abs could be a useful marker for PTC.

Overexpression of FOXO3, MYD88, and GAPDH Identified by Suppression Subtractive Hybridization in Esophageal Cancer Is Associated with Autophagy

To find genes involved in tumorigenesis and the development of esophageal cancer, the suppression subtractive hybridization (SSH) method was used to identify genes that are overexpressed in esophageal cancer tissues compared to normal esophageal tissues. In our SSH library, the forkhead box O3 (FOXO3), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and myeloid differentiation primary response 88 (MYD88) genes were the most highly upregulated genes, and they were selected for further studies because of their potential role in the induction of autophagy. Upregulation of these genes was also observed in clinical samples using qRT-PCR. In addition, coexpression analysis of the autophagy-related genes Beclin1, ATG12, Gabarapl, PIK3C3, and LC3 demonstrated a significant correlation between the differentially overexpressed genes and autophagy. Autophagy is an important mechanism in tumorigenesis and the development of chemoresistance in cancer cells. The upregulation of FOXO3, GAPDH, and MYD88 variants in esophageal cancer suggests a role for autophagy and provides new insight into the biology of esophageal cancer. We propose that FOXO3, GAPDH, and MYD88 are novel targets for combating autophagy in esophageal cancer.

P53, COX-2, iNOS Protein Expression Changes and Their Relationship with Anti-Oxidant Enzymes in Surgically and Multi-Modality Treated Esophageal Carcinoma Patients

Esophageal carcinoma has a high incidence in India but its etiology remains unknown. In the present study the correlation between apoptosis regulatory proteins and anti-oxidant enzymes in 40 esophageal carcinoma patients was examined. Patients in one group were operated by transhiatal esophagectomy and in the second group were administered cisplatin (30 mg/m2/day) and 5-fluorouracil (5-FU) (750 mg/m2/day) daily for three days followed by surgery after four weeks of neo-adjuvant therapy (NAT). Complete pathological response was achieved in 15% of patients. Results obtained by Western blot analysis showed over-expressed p53 and COX-2 protein levels in the tumor tissues as compared to the adjoining tissue and its paired normal mucosa in both groups of patients. Immunohistochemical studies showed heterogenous p53 staining pattern with sections showing both nuclear and cytoplasmic staining with 36.8% mild, 10.5% moderate and 52.6% intense p53 immunoreactivity. Both COX-2 and iNOS immunostaining revealed 25% negative and 75% mild to strongly positive immunoreactivity. Correlation studies demonstrated a positive relationship between p53 and COX-2 (P=0.030; r = +0.70) in surgically treated patients. The association of COX-2 and p53 with various anti-oxidant enzymes showed a significantly positive correlation between COX-2 expression and catalase activity and an inverse correlation between p53 expression and superoxide dismutase and catalase activity in the tumor tissue of patients given NAT. In addition, we observed a negative trend between p53 expression levels and GPx enzyme levels in both the adjoining and tumor tissue of patients having undergone surgery as main mode of treatment.

Circulating autoantibody to FOXP3 may be a potential biomarker for esophageal squamous cell carcinoma

The present study was undertaken to develop a relatively quantitative enzyme-linked immunosorbent assay (ELISA) in-house using human leukocyte antigen class II-restricted epitopes in order to test circulating autoantibodies to human forkhead/winged helix transcription factor (FOXP3) as a biomarker for esophageal cancer. A total of 97 patients with esophageal squamous cell carcinoma (ESCC) and 227 healthy subjects were recruited for this study, and their plasma samples were collected for antibody analysis with the ELISA approach. Student's t test showed that the anti-FOXP3 IgG antibody levels were significantly higher in the patient group than the control group (t=6.23, P<0.0001). Based on a cutoff value determined by the mean+3SD of control IgG levels, the positive rate was 5.15 % in patients with ESCC as compared to 0.88 % in control subjects (X (2) =6.53, P=0.019, OR=5.85, 95 % CI 1.12-30.67), in which patients at stage I had the highest positivity (11.54 %, X (2) =12.15, P=0.0005, OR=13.10, 95 % CI 2.09-82.04). The sensitivity against >95 % specificity was 22.7 % for the IgG assay with an inter-assay deviation of 13.35 %. This work suggests that circulating IgG autoantibody to FOXP3 may be a potential biomarker for early diagnosis of esophageal cancer.

Circulating autoantibody to CD25 may be a potential biomarker for early diagnosis of esophageal squamous cell carcinoma

BACKGROUND

The present study was undertaken to develop an in-house enzyme-linked immunosorbent assay (ELISA) using human leukocyte antigen class II restricted epitopes to test circulating autoantibodies to CD25 as a biomarker for esophageal cancer.

METHODS

A total of 97 patients with esophageal squamous cell carcinoma (ESCC) and 226 healthy subjects were recruited for this study and their plasma samples were collected for antibody analysis with the ELISA approach.

RESULTS

Mann-Whitney U test showed that the IgG anti-CD25 antibody level was significantly higher in the patient group than the control group (P < 0.001) while the IgA antibody level was not significantly different between these two groups (P = 0.361). Spearman correlation analysis failed to reveal a significant correlation between the levels of anti-CD25 IgG and IgA antibodies in either the patient group (r = -0.027, P = 0.797, n = 94) or the control group (r = 0.055, P = 0.429, n = 209). The sensitivity against >90 % specificity was 37.2 % for the IgG assay with an inter-assay deviation of 9.4 %, and 8.2 % for the IgA assay with an inter-assay deviation of 13.0 %. Based on a cut-off value determined by the 99th percentile of control IgG levels, the positive rate was 7.4 % in patients with ESCC, in which patients at stage I had the highest positivity (11.5 %) (χ (2) = 11.10, P = 0.001, OR = 12.12, 95 % CI 1.93-75.94).

CONCLUSIONS

This work suggests that circulating IgG autoantibody to CD25 may be a potential biomarker for early diagnosis of esophageal cancer.

Circulating autoantibody to ABCC3 may be a potential biomarker for esophageal squamous cell carcinoma

PURPOSE

There is an urgent need to identify biomarkers for early diagnosis and prognosis of esophageal cancer. The present study was undertaken to test whether circulating autoantibodies to ATP-binding cassette C3 (ABCC3) transporter could serve as a biomarker for the malignant tumor.

METHODS

An enzyme-linked immunosorbent assay approach was developed in-house to test circulating autoantibodies to ABCC3 in 114 patients with esophageal squamous cell carcinoma (ESCC) and 226 healthy subjects well matched in age and smoking history.

RESULTS

Mann-Whitney U test showed that the IgA antibody levels were significantly higher in patients with ESCC than control subjects (Z = -4.226, P < 0.001) while the IgG antibody levels were not significantly different between the two groups (Z = -1.072, P = 0.284). The sensitivity against >95 % specificity was 13.2 % for the IgA assay with an inter-assay deviation of 13.0 and 7.9 % for the IgG assay with an inter-assay deviation of 9.4 %.

CONCLUSIONS

This work suggests that circulating IgA autoantibody to ABCC3 may be a potential biomarker for ESCC, which could be used for early diagnosis and prognosis of the malignant tumor.

Potential diagnostic value of serum p53 antibody for detecting esophageal cancer: a meta-analysis

BACKGROUND

Mutant p53 protein overexpression has been reported to induce serum antibodies against p53. Various studies assessing the diagnostic value of serum p53 antibody in patients with esophageal cancer remain controversial. This study aims to comprehensively and quantitatively summarize the potential diagnostic value of serum p53 antibody in esophageal cancer.

METHODS

We systematically searched PubMed and Embase until 31st May 2012, without language restriction. Studies were assessed for quality using QUADAS (quality assessment of studies of diagnostic accuracy). Positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were pooled separately and compared with overall accuracy measures diagnostic odds ratio (DOR) and symmetric summary receiver operating characteristic (sROC). The PLR and NLR and their 95% confidence interval (CI) were calculated using a fixed effects model according to the Mantel-Haensed method and random effects model based on the work of Der Simonian and laird, respectively.

RESULTS

Fifteen studies (cases = 1079, controls = 2260) met the inclusion criteria for the meta-analysis. Approximately 53.33% (8/15) of the included studies were of high quality (QUADAS score≥8), which were retrospective case-control studies. The summary estimates for quantitative analysis of serum p53 antibody in the diagnosis of esophageal cancer were PLR 6.95 (95% CI: 4.77-9.51), NLR 0.75 (95%CI: 0.72-0.78) and DOR 9.65 (95%CI: 7.04-13.22). However, we found significant heterogeneity between NLRs.

CONCLUSIONS

The current evidence suggests serum p53 antibody has a potential diagnostic value for esophageal cancer. However, its discrimination power is not perfect because of low sensitivity.

IMPACT

These results suggest that s-p53-antibody may be useful for monitoring residual tumor cells and for aiding in the selection of candidates for less invasive treatment procedures because of the high specificity of s-p53-antibody. Further studies may need to identify patterns of multiple biomarkers to further increase the power of EC detection.

Reevaluation of serum p53 antibody as a tumor marker in colorectal cancer patients

PURPOSE

We reevaluated the serum p53 antibody (S-p53Ab) ELISA kit, which was approved as a tumor marker of colon cancer in the Japanese Health Insurance System in 2007.

METHODS

S-p53Ab was measured as a tumor marker in 154 colorectal cancer patients, and the results were categorized by clinical and pathological variables. We then compared the positive frequency of S-p53Ab, carcinoembryonic antigen (CEA), and carbohydrate 19-9 (CA19-9).

RESULTS

S-p53Ab was positive in 33.1% of the colorectal cancer patients. The positive rate was significantly higher in patients with lymph nodes metastasis (P = 0.025) and lymphatic invasion (P = 0.023). In patients with stage I colorectal cancer, the positive rate of S-p53Ab (23.7%) was significantly higher than that of CEA (5.3%) or CA19-9 (7.9%).

CONCLUSION

The approved kit for S-p53Ab testing was found to be an effective tumor marker of colorectal cancer. The positive rate of S-p53Ab was significantly higher in patients with cancer involvement of the lymphoid tissues. The positive rate of S-p53Ab was higher than that of CEA and CA19-9 in patients with stage I colorectal cancer, suggesting that the S-p53Ab is a useful tumor marker for patients with early-stage disease.

Mutations in the p53 Tumor Suppressor Gene: Important Milestones at the Various Steps of Tumorigenesis

Inactivation of the p53 tumor suppressor is a frequent event in tumorigenesis. In most cases, the p53 gene is mutated, giving rise to a stable mutant protein whose accumulation is regarded as a hallmark of cancer cells. Mutant p53 proteins not only lose their tumor suppressive activities but often gain additional oncogenic functions that endow cells with growth and survival advantages. Interestingly, mutations in the p53 gene were shown to occur at different phases of the multistep process of malignant transformation, thus contributing differentially to tumor initiation, promotion, aggressiveness, and metastasis. Here, the authors review the different studies on the involvement of p53 inactivation at various stages of tumorigenesis and highlight the specific contribution of p53 mutations at each phase of cancer progression.

Prognostic and diagnostic value of spontaneous tumor-related antibodies

There is an urgent need for earlier diagnosis of malignancies and more stringent monitoring of relapses after antitumor therapy. In addition, new prognostic markers are needed for risk stratification and design of individualized cancer therapies. New diagnostic and prognostic parameters should overcome the impairments of current standards in a cost-effective manner. Serological approaches measuring spontaneous antibody responses against tumor-associated antigens could be of use as diagnostic and prognostic markers and could also be employed to evaluate response to therapy in cancer patients. Autoantibodies have been suggested to be of frequent and specific occurrence in patients with malignancies and to correlate with clinical parameters. Screening the relevant literature on this topic, we suggest that the analysis of single antibody specificities is unlikely to provide sufficient diagnostic and prognostic accuracy. The combined analysis of autoantibodies targeting different antigens, however, may reach high sensitivity and specificity. In addition, screening cancer patients for autoantibodies might identify subgroups with high relapse risk and a worse prognosis. Larger prospective trials should be initiated to identify sets of tumor-associated autoantibodies suited for the use in diagnostic algorithms for cancer detection and followup.

Specific intronic p53 mutation in esophageal squamous cell carcinoma in Southern Thailand

AIM

To investigate p53 mutations in esophageal cancer in a high-risk population, and correlate them with smoking, alcohol consumption and betel chewing.

METHODS

One hundred and sixty-five tumor samples of esophageal squamous cell carcinoma (ESCC) obtained from a university hospital in Songkhla province, Southern Thailand were investigated for p53 mutations in exons 5-8, using polymerase chain reaction-single strand conformation polymorphism analysis, followed by direct sequencing. A polymerase chain reaction-restriction fragment length polymorphism (RFLP) assay was additionally used to confirm possible germline mutation in intron 6. A history of risk habits was obtained by interviews. The association between risk habits and mutation frequency was evaluated using the χ(2) test.

RESULTS

The studied specimens were from 139 male and 26 female patients with ESCC, treated at Songklanagarind Hospital. Most of the patients were smokers (86.7%) and alcohol consumers (72.73%), and 38.3% were betel chewers. Forty-three mutations of the p53 gene were detected in 25.5% (42/165) of tumor samples. Mutations were most commonly found in exon 5 (25.6%) and exon 8 (25.6%). Mutations in the hot-spot codon 248 were found in four cases (9.3% of all mutations). G:C→C:G (30.23%), G:C→A:T (27.90%) and G:C→T:A (16.28%) were the prevalent spectra of mutations. Unexpectedly, among 10 intronic mutations, eight cases harbored a similar mutation: G→C substitution in intron 6 (nucleotide 12759, GenBank NC_000017). These were additionally confirmed by the RFLP technique. Similar mutations were also detected in their matched blood samples using RFLP and direct sequencing, which suggested germline mutations. There was no significant correlation between risk habits and p53 mutation frequency.

CONCLUSION

A proportion of Thai ESCC patients harbored specific intronic p53 mutations, which might be germline mutations. Further studies are needed to explore this novel finding.

Anti-CDC25B autoantibody predicts poor prognosis in patients with advanced esophageal squamous cell carcinoma

Background

The oncogene CDC25B phosphatase plays an important role in cancer cell growth. We have recently reported that patients with esophageal squamous cell carcinoma (ESCC) have significantly higher serum levels of CDC25B autoantibodies (CDC25B-Abs) than both healthy individuals and patients with other types of cancer; however, the potential diagnostic or prognostic significance of CDC25B-Abs is not clear. The aim of this study is to evaluate the clinical significance of serum CDC25B-Abs in patients with ESCC.

Methods

CDC25B autoantibodies were measured in sera from both 134 patients with primary ESCC and 134 healthy controls using a reverse capture enzyme-linked immunosorbent assay (ELISA) in which anti-CDC25B antibodies bound CDC25B antigen purified from Eca-109 ESCC tumor cells. The clinicopathologic significance of CDC25B serum autoantibodies was compared to that of the tumor markers carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC-Ag) and cytokeratin 19 fragment antigen 21-1(CYFRA21-1).

Results

Higher levels of CDC25B autoantibodies were present in sera from patients with ESCC (A₄₅₀ = 0.917, SD = 0.473) than in sera from healthy control subjects (A₄₅₀ = 0.378, SD = 0.262, P < 0.001). The area under the receiver operating characteristic (ROC) curve for CDC25B-Abs was 0.870 (95% CI: 0.835-0.920). The sensitivity and specificity of CDC25B-Abs for detection of ESCC were 56.7% and 91.0%, respectively, when CDC25-Abs-positive samples were defined as those with an A₄₅₀ greater than the cut-off value of 0.725. Relatively few patients tested positive for the tumor markers CEA, SCC-Ag and CYFRA21-1 (13.4%, 17.2%, and 32.1%, respectively). A significantly higher number of patients with ESCC tested positive for a combination of CEA, SCC, CYFRA21-1 and CDC25B-Abs (64.2%) than for a combination of CEA, SCC-Ag and CYFRA21-1 (41.0%, P < 0.001). The concentration of CDC25B autoantibodies in serum was significantly correlated with tumor stage (P < 0.001). Although examination of the total patient pool showed no obvious relationship between CDC25B autoantibodies and overall survival, in the subgroup of patients with stage III-IV tumors, the cumulative five-year survival rate of CDC25B-seropositive patients was 6.7%, while that of CDC25B-seronegative patients was 43.4% (P = 0.001, log-rank). In the N1 subgroup, the cumulative five-year survival rate of CDC25B-seropositive patients was 13.6%, while that of CDC25B-seronegative patients was 54.5% (P = 0.040, log-rank).

Conclusions

Detection of serum CDC25B-Abs is superior to detection of the tumor markers CEA, SCC-Ag and CYFRA21-1 for diagnosis of ESCC, and CDC25B-Abs are a potential prognostic serological marker for advanced ESCC.

A systematic review of humoral immune responses against tumor antigens

This review summarizes studies on humoral immune responses against tumor-associated antigens (TAAs) with a focus on antibody frequencies and the potential diagnostic, prognostic, and etiologic relevance of antibodies against TAAs. We performed a systematic literature search in Medline and identified 3,619 articles on humoral immune responses and TAAs. In 145 studies, meeting the inclusion criteria, humoral immune responses in cancer patients have been analyzed against over 100 different TAAs. The most frequently analyzed antigens were p53, MUC1, NY-ESO-1, c-myc, survivin, p62, cyclin B1, and Her2/neu. Antibodies against these TAAs were detected in 0-69% (median 14%) of analyzed tumor patients. Antibody frequencies were generally very low in healthy individuals, with the exception of few TAAs, especially MUC1. For several TAAs, including p53, Her2/neu, and NY-ESO-1, higher antibody frequencies were reported when tumors expressed the respective TAA. Antibodies against MUC1 were associated with a favorable prognosis while antibodies against p53 were associated with poor disease outcome. These data suggest different functional roles of endogenous antibodies against TAAs. Although data on prediagnostic antibody levels are scarce and antibody frequencies for most TAAs are at levels precluding use in diagnostic assays for cancer early detection, there is some promising data on achieving higher sensitivity for cancer detection using panels of TAAs.

Perioperative changes of serum p53 antibody titer is a predictor for survival in patients with esophageal squamous cell carcinoma

BACKGROUND

Although the presence of serum p53 antibody (s-p53-Abs) before treatment has been shown to correlate with poor prognosis and lymph node metastasis in esophageal cancer, there has been little information about postoperative s-p53-Abs titer and perioperative changes of s-p53-Abs titers in patients with esophageal carcinoma.

METHODS

A highly specific enzyme-linked immunosorbent assay was used to analyze s-p53-Abs in 110 patients with esophageal squamous cell carcinoma before and 1 month after surgery. The cutoff level of 1.3 U/ml was used to indicate seropositive patients. Impact of postoperative s-p53-Abs titer and perioperative changes of s-p53-Abs on survival was evaluated.

RESULTS

Forty (36%) of 110 patients were positive for s-p53-Abs before surgery and 35 patients (32%) were positive after surgery. s-p53-Abs titer generally decreased after surgery. Among sero-positive patients, the patients who remained sero-positive after surgery (n = 28) had a worse prognosis than patients who showed sero-conversion (P = 0.02). Among sero-positive patients, the nondecreased titer group showed significantly unfavorable survival (P < 0.01). Multivariate analysis revealed that postoperative s-p53-Abs was an independent risk factor for worse overall survival (adjusted hazard ratio = 3.05; 95% confidence interval = 1.11-8.33; P = 0.03).

CONCLUSIONS

Perioperative monitoring of s-p53-Abs titers was useful to identify patients with esophageal cancer with a high risk for tumor recurrence and a poor prognosis. Continuous sero-positive patients and/or nondecreased titer group, even after surgery, showed significantly unfavorable survival.

Proteomics-based identification of autoantibody against CDC25B as a novel serum marker in esophageal squamous cell carcinoma

This study was aimed to identify tumor proteins that elicit a humoral response in patients with esophageal squamous cell carcinoma (ESCC). Autologous sera of 15 newly diagnosed patients with ESCC and age- and gender-matched 15 healthy controls were analyzed individually for antibody-based reactivity against proteins from 15 homogenized ESCC tissue mixture resolved by two-dimensional PAGE. One protein spot, which reacted with sera from ESCC patients but not with those from controls, was identified to be CDC25B by mass spectrometry and Western blotting. High expression of CDC25B was detected in ESCC cell lines and primary tumor tissues, but not in normal esophageal tissues. In addition, CDC25B expression was significantly higher in tumor tissue of patients with sera positive CDC25B-Abs than that of patients without CDC25B-Abs. Finally, anti-CDC25B antibodies were readily detectable in sera from 45 of 124 (36.29%) patients with ESCC, 13 of 150 (8.67%) patients with other types of cancer and 0 of 102 (0%) of healthy individuals. Thus, CDC25B autoantibodies may have clinical utility in ESCC screening and diagnosis.

Serum p53 antibody as a diagnostic marker of high-risk endometrial cancer

OBJECTIVE

The purpose of this study was to investigate the diagnostic impact of preoperative serum p53 antibody (S-p53 Ab) in patients with endometrial cancer.

STUDY DESIGN

A hospital-based series of 67 patients, comprising 58 endometrioid adenocarcinomas (EA) and 9 serous adenocarcinomas (SA) between 1998-2002 were included. First, preoperative pathology was compared with final pathology in terms of histologic classification and tumor grade. Second, S-p53 Ab and CA125 were measured using preoperative serum samples, and immunohistochemical staining for p53 protein was assessed using hysterectomy specimens.

RESULTS

There were discrepancies between preoperative and final pathology in terms of histologic classification (7%) and tumor grade in EAs (30%); other objective tests, therefore, were needed to minimize the diagnostic problems. S-p53 Ab titers varied from 0.27-786 (mean, 124) in SAs and from 0.1-7.47 (mean, 0.46) U/mL in EAs, respectively, and were positive in 6 (67%) SAs and in 3 (6%) EAs using 1.3 U/mL as cut-off. S-p53 Ab-positive rate was significantly correlated with SA histology and grade 3 EA tumor (odds ratio, 40; P = .005; 95% confidence interval, 3.04-525.43) with higher sensitivity and higher specificity than p53 staining and CA125, respectively.

CONCLUSION

S-p53 Ab could conveniently and specifically identify high-risk endometrial cancer.

The clinical significance of autoantibodies in gastrointestinal malignancies: an overview

Autoimmunity can be associated with cancer and one of the forms of its expression is the development of antibodies to autologous cellular antigens. The types of cellular proteins which induce autoantibody responses in gastrointestinal malignancies are quite varied and include cellular proteins encoded by mutated normal genes (p53), cellular proteins that are overexpressed and/or aberrantly expressed in malignant tissues (carcinoembryonic antigen), inhibitors of apoptosis (survivin and livin), major components of mucus (mucins), surface receptors of apoptosis (Fas) and nuclear-restricted proteins (double-stranded DNA, single-stranded DNA and Sm family proteins). In the past few years, due to the great clinical interest and the advancement in detection techniques, the above list has grown significantly and a large number of cancer-related antigens, which trigger a specific humoral immune response to the host, have also been identified. The authors review the autoantibodies associated with gastrointestinal malignancies and their clinical implications.

Risk of p53 gene mutation in esophageal squamous cell carcinoma and habit of betel quid chewing in Taiwanese

A recent report suggested that BQ (BQ) chewing significantly correlated with the occurrence of esophageal squamous cell carcinoma (ESCC) in Taiwanese. BQ chewing was shown to be associated with p53 mutation in oral cancers. However, the relationship between BQ chewing and p53 mutation in ESCC is unclear. Seventy-five primary ESCC patients were enrolled for mutational analysis of the p53 gene using polymerase chain amplification and direct sequencing of amplified product. Thirty-seven mutations of the p53 gene were detected in 45.5% (34/75) of tumor specimens. These mutations significantly clustered in exon 5 (21/37) of the p53 gene. The incidence of p53 mutations did not associate with clinicopathological characteristics or the habits of cigarette smoking or alcohol consumption. However, BQ chewers exhibited significantly higher incidence of p53 gene mutations than non-chewers (67.6% vs 32.4%, P = 0.007). After controlling the confounding factors of cigarette smoking and alcohol intake, BQ chewing still showed significant association with the incidence of p53 mutation in ESCCs (RR = 4.23; 95% CI, 1.317-13.60). The A:T to G:C transition (8/37, 21.6%) and G:C to T:A transversion (5/23, 13.5%) were the prevalent spectrum of p53 gene mutations. All A:T to G:C transitional mutations occurred in patients with the habits of BQ chewing and cigarette smoking. Noticeably, alcohol consumption could enhance this peculiar spectrum of p53 mutation in ESCC. Accordingly, p53 might be an important molecular target of BQ carcinogens in the development of ESCC in Taiwanese.

Immune responses to DNA mismatch repair enzymes hMSH2 and hPMS1 in patients with pancreatic cancer, dermatomyositis and polymyositis

To identify tumor antigens useful for diagnosis and immunotherapy of patients with pancreatic ductal adenocarcinoma, we applied a SEREX approach with a cDNA library made from 5 pancreatic cancer cell lines and sera obtained from 8 patients with pancreatic cancer, and isolated total 32 genes, including 14 previously characterized genes and 18 genes with unknown functions. Among these isolated antigens, serum IgG antibodies for 2 isolated DNA mismatch repair enzymes, Homo sapiens mutS homolog 2 (hMSH2) and Homo sapiens postmeiotic segregation increased 1 (hPMS1), were detected in patients with pancreatic ductal adenocarcinoma and dermatomyositis (DM), and polymyositis (PM), but not in sera from healthy individuals. Immunohistochemical study demonstrated that hMSH2 and hPMS1 were over-expressed in pancreatic ductal adenocarcinoma compared to normal pancreatic ducts. These results suggested that hMSH2 and hPMS1 may be useful as CD4+ helper T cell antigens for immunotherapy of pancreatic cancer patients and that serum IgG antibodies may be useful for diagnosis of patients with pancreatic ductal adenocarcinoma and DM/PM.

p53 mutation profile of squamous cell carcinomas of the esophagus in Kashmir (India): a high-incidence area

Esophageal squamous cell carcinoma (ESCC) has been reported to show geographical variation in its incidence, even within areas of ethnic homogeneity. Kashmir valley, in north of India, has been described as a high-risk area for ESCC. Here, we make a preliminary attempt to study mutations in exons 5-8 (the DNA binding domain) of the tumor suppressor gene, p53, in 55 ESCC patients from Kashmir. Polymerase chain reaction followed by direct sequencing analysis revealed the presence of mutations in 36.36% (20/55) tumors, assessed for the extent of allelic instability. The 20 mutations, found in 20 patients, comprised of 17 single-base substitutions (11 transitions + 6 transversions) and 3 deletions. The 17 single-base variations represented 12 missense mutations, 2 nonsense mutations and 3 variations located in intron 6, 1 of which resulted in a splicing variant. The patients when compared for the incidence of p53 mutation with various demographic features revealed females to be at increased risk (p = 0.016; OR = 4.13; 95% CI = 1.26-13.46). Comparison of mutation profile with other high-risk areas reflected both differences and similarities indicating coexposure to a unique set of risk factors. This might be due to the special dietary and cultural practices of Kashmir that needs validation, as does the gender-based difference in the incidence of p53 mutation observed in this study.

p53 gene mutation and human papillomavirus (HPV) infection in esophageal carcinoma from three different endemic geographic regions of India

Infection of high-risk human papillomaviruses (HPVs), particularly the HPV types 16 and 18 and mutation or aberrant expression of the p53 tumour suppressor gene, has strongly been implicated in human esophageal carcinoma, which shows a great variation in geographic distribution. Neither the reason(s) for such a variation nor the etiopathogenesis of the disease is clearly understood. The present study has been carried out to determine prevalence of high-risk HPV types 16 and 18 and the p53 gene mutation in patients from three distinctly different endemic geographic regions of India, viz. Kashmir, Dibrugarh, and New Delhi where esophageal cancer is most prevalent. The people from each of these regions differ considerably in their food, drinking, smoking and chewing habits (tobacco and betel nut) and ethnic background. While PCR was employed to detect high-risk HPV types 16 and 18 DNA sequences, PCR-SSCP and direct nucleotide sequencing was used for analysis of p53 mutation. Out of a total of 101 biopsy specimens of carcinoma esophagus analysed, the frequency of HPV was found to be the highest 14/32 (44%) in Dibrugarh followed by 33% (11/33) in Kashmir, but, interestingly, no high-risk HPV could be detected in New Delhi patients who showed the highest frequency (30.6%) of p53 mutation as against only 12.5% in Dibrugarh and 6.1% in Kashmir. The difference in the frequency of p53 mutation between the three regions was statistically highly significant (0.018). Out of a total of 21 nucleotide alterations observed, 12 missense, five frameshift and four were silent changes. The p53 exon 7 appears to be the 'hot-spot' for esophageal cancer as it alone was responsible for more than 76% (13/17) of mutations and more than 95% (20/21) of the patients with p53 mutation were smokers. The results demonstrate differential distribution of HPV infection and p53 mutation in esophageal cancer from different geographic regions of India and this could be due to variation in diet, drinking, and tobacco habit, including ethnic, socio-cultural and genetic variation.

Titration of serum p53 antibodies in 1,085 patients with various types of malignant tumors: a multiinstitutional analysis by the Japan p53 Antibody Research Group

BACKGROUND

There have been very few large-scale, multiinstitutional studies of surveillance of serum p53 antibodies (S-p53 Abs) in patients with various malignant tumors.

METHODS

A highly specific, quantitative enzyme-linked immunosorbent assay (ELISA) kit was developed and used to evaluate the efficiency of detecting p53 Abs. A cut-off value was established by analyzing sera from 205 healthy volunteers as reference individuals. Sera from 1085 patients with various types of primary malignant tumors were studied for the presence of S-p53 Abs before treatment. Sera from 34 patients were selected randomly for a competition assay to ensure that antibodies were specific to p53 protein. Carcinoembryonic antigen (CEA) was assessed to compare its positive rate with the positive rate of S-p53 Abs.

RESULTS

The median value of S-p53 Abs in healthy control individuals was 0.33 U/mL (range, 0.0-4.39 U/mL). Based on reference values that were calculated using parametric determination of the lower 0.95 fraction of the reference distribution in healthy control individuals, the cut-off value was determined as 1.3 U/mL. Two hundred twenty-one of 1085 patients (20.4%) were positive for S-p53 Abs. The highest relevance of S-53 Abs was associated with head and neck carcinoma (32%), followed by esophageal carcinoma (30%), colorectal carcinoma (24%), and carcinoma of the uterus (23%). The positive rate for S-p53 Abs was higher compared with the positive rate for CEA in patients with squamous cell carcinoma.

CONCLUSIONS

Surveillance of S-p53 Abs is useful in detecting various types of malignant tumors, particular in patients with squamous cell carcinoma.

Treatment response and prognosis of patients after recurrence of esophageal cancer

BACKGROUND

Although radical operation and adjuvant chemoradiotherapy improve survival in patients with advanced esophageal cancer, more than half of these patients have recurrence. The aim of this study was to explore treatment responses and prognostic factors in patients with recurrent esophageal cancer.

METHODS

The operative specimens from 258 patients undergoing radical esophagectomy with extended lymphadenectomy for esophageal squamous cell carcinoma between 1990 and 1999 were analyzed. Depth of tumor invasion, and the extent and location of lymph node metastases were determined. Postoperative recurrence was identified from positive findings on successive 3-month examinations of tumor markers, 6-month examinations of ultrasonography, and annual computed tomography. Of 258 patients, 95 had recurrence by the end of 2000 (mean follow-up was 22 months, range, 2-113). Of those 95 patients, 76 received nonsurgical treatment, 7 received operative intervention, and 12 received no treatment. Clinicopathologic features of recurrent tumors were analyzed to determine prognostic values. Serum anti-p53 antibodies (S-p53-Abs), serum C-reactive protein concentration (S-CRP), and albumin concentration were also analyzed.

RESULTS

The main recurrent patterns were nodal (n = 45) and organ (n = 35). Of the nonsurgical treatment group, 47 patients received chemoradiotherapy; 17, chemotherapy; and 12, radiotherapy. Overall clinical response was observed in 26 of 76 patients (34%). Treatment response was significantly associated with the type of recurrence, history of perioperative adjuvant therapy, time of recurrence, number of recurrent tumors, albumin concentration, S-CRP, and S-p53-Abs. Multivariate analysis suggested that S-p53-Abs and S-CRP were independent prognostic factors.

CONCLUSION

The status of S-p53-Abs and S-CRP may predict response and outcome of patients with recurrence of esophageal cancer after radical operation.

Prognostic significance of serum p53 antibody in patients with esophageal squamous cell carcinoma

BACKGROUND

The p53 protein overexpression that usually results from genetic alterations has been reported to induce serum antibodies against p53. There is little information about the clinicopathologic and prognostic significance of preoperative serum p53 antibody in patients with esophageal cancer.

METHODS

A highly specific enzyme-linked immunosorbent assay was used to analyze serum p53 antibodies in 105 patients with esophageal squamous cell carcinoma. The cutoff level of 1.3 U/mL was used to indicate seropositive patients, and the cutoff level of 10 U/mL was used to identify high titer patients. At 3 months after surgery, seropositive patients were examined again.

RESULTS

A total of 28 patients (26.7%) were positive for serum p53 antibodies. The patients who remained seropositive were more likely to develop tumor recurrence (P =.025). Seropositive patients had worse outcome than seronegative patients. The high titer group had significant association with advanced tumor stages and worse outcomes than the low titer group. High serum p53 antibody titer was an independent prognostic factor (P <.001).

CONCLUSIONS

We found that serum p53 antibody was useful to detect esophageal cancer and to identify those with a high risk of tumor recurrence and a poor prognosis.

Increase in immune cell infiltration with progression of oral epithelium from hyperkeratosis to dysplasia and carcinoma

In the present study, epithelium derived lesions of various pathological manifestations were examined histologically and immunohistochemically for mononuclear cell infiltration. The infiltrate under the transformed epithelium of oral lesions, was examined for differences in the composition of immune mononuclear cells as the epithelium moves from hyperkeratosis through various degrees of dysplasia to squamous cell carcinoma. The study was performed on 53 human tongue tissues diagnosed as hyperkeratosis (11 cases), mild dysplasia (nine cases), moderate and severe dysplasia (14 cases) and squamous cell carcinoma (19 cases). A similar analysis was performed on 30 parotid gland tissues diagnosed as pleomorphic adenoma (14 cases) and carcinoma ex-pleomorphic adenoma (16 cases). Immunohistochemical analysis of various surface markers of the tumour infiltrating immune cells was performed and correlated with the transformation level as defined by morphology and the expression of p53 in the epithelium. The results revealed that, in the tongue lesions, the changes in the epithelium from normal appearance to transformed were accompanied by a corresponding increase in the infiltration of CD4, CD8, CD14, CD19+20, and HLA/DR positive cells. The most significant change was an increase in B lymphocytes in tongue lesions, that was in accordance with the transformation level (P<0.001). In the salivary gland, a significant number of cases did not show an infiltrate. In cases where an infiltrate was present, a similar pattern was observed and the more malignant tissues exhibited a higher degree of immune cell infiltration.

Gene mutation as a target for early detection in cancer diagnosis

The increasing number of genetic aberrations implicated in the development of human cancer has prompted a search to detect them at the earliest possible stage of their formation. Of the many such genetic changes identified thus far, relatively few meet the standard for markers in early diagnosis and prognosis, namely that the genetic modifications occur during the early onset phase of cancer development. Parallel to the increasing number of such genes is the growing availability of technologies using more powerful and cost-efficient methods that enable mass screening for genetic alterations. The purpose of this review is to summarize the currently available genes that can serve as markers for early detection of cancers and methods that allow their detection.

Low detection rate of p53 antibodies in sera of soft tissue sarcoma patients

Accumulation of the p53 gene product can lead to its immunogenic appearance and the generation of p53 serum antibodies (p53ab). In different cancer types the occurrence of detectable p53ab has an independent prognostic impact. In spite of the known p53 protein overexpression rate in soft tissue sarcomas (STS), up to 70%, there have been no investigations done on p53ab in serum in STS patients. In this prospective study of 50 STS patients, we investigated the presence of serum p53ab using an enzyme-linked immunosorbent assay system and the presence of p53 overexpression in the appropriate tissue specimen immunohistochemically. Using Kruskal-Wallis chi(2) and Kaplan-Meier tests the results were then correlated to histopathological and clinical data. Six of the 50 patients (12%) showed p53ab detectable in the serum, and 56% (28/50) of the tumors were p53 immunohistochemically positive. Four of the six p53ab positives (66%) had immunohistochemically p53 positive and two (33%) had negative tumors. Altogether four of the 50 patients (8%) were positive for p53ab in serum as well as for p53 immunohistochemistry in tumor tissue specimens. Twenty patients (40%) were negative for both. All of the p53ab positive patients had stage I or II tumors. Excluding tumor stage there was no p53ab correlation to histopathological, clinical or prognostic parameters. We conclude that in STS patients, p53ab also occurs but in contrast to other tumor types at a relatively low frequency. According to our results, the clinical value of p53ab seems to be limited in STS patients.

Cloning and characterization of full-length human ribosomal protein L15 cDNA which was overexpressed in esophageal cancer

The aim of this investigation was trying to identify the genes differentially expressed in esophageal cancer. By combining suppression subtractive hybridization (SSH) with reverse Northern high density blots, a gene named EC45 was obtained, which dramatically overexpressed in 70% esophageal cancer (18/26). EC45 was mapped to 3p12-3p11.2 by radiation hybrid mapping (RH mapping). The putative full length EC45 cDNA (1987 bp) was identified by cDNA libraries screening of esophageal cancer. EC45 encoded 204 amino acids, and it shared a 100% similarity with ribosomal protein L15 (635 bp, mRNA) in ORF, but no similarity in 5' UTR or 3' UTR. Northern blot panel of multiple adult human normal tissues showed EC45 distributed in almost normal tissues tested. All these data suggested that EC45, encoding ribosomal protein L15 and overexpressing in esophageal cancer might play a possible role in carcinogenesis of esophagus.

Alterations in MDM2 expression in esophageal squamous cell carcinoma: relationship with p53 status

In view of the significance of MDM2 as a regulator as well as critical target of wild type p53, this study was undertaken to determine the alteration in MDM2 expression in esophageal squamons cell carcinoma (ESCC) and its relationship to clinicopathological parameters as well as p53gene and protein status. Immunohistochemical analysis of MDM2 and p53 proteins on paraffin embedded sections from 64 surgically resected ESCCs and matched histologically normal tissues showed overexpression of MDM2 protein in 23/64 (36%) ESCCs, while the histopathologically normal esophageal tissues did not show detectable level of MDM2 immunoreactivity. Interestingly, MDM2 /p53 + phenotype was observed in 37/64 (58%) cases. None of the cases with p53 mis-sense mutations (12/30, 40%) showed detectable level of MDM2 protein. Missense p53 mutations were significantly associated with discordant p53 + /MDM2 immunophenotype (p= 0.004). The most intriguing feature of the study was accumulation of MDM2 in the absence of detectable p53 in 11% of and overexpression of MDM2 and p53 in 25% of ESCCs, suggesting a p53-independent role for MDM2 in a subset of tumors. These results underscore the involvement of MDM2 in p53-dependent and -independent pathways in the pathogenesis of esophageal cancer in the Indian population.

Serum p53 antibody is a useful tumor marker in superficial esophageal squamous cell carcinoma

BACKGROUND

Patients with superficial (mucosal or submucosal) esophageal carcinoma (SEC) have significantly better survival rates than patients with advanced carcinoma. Some patients with advanced esophageal carcinoma have been reported to test positive for serum p53 antibodies (Abs). Because very few patients with superficial carcinoma have been examined, the aim of this study was to evaluate the clinical significance of serum p53-Abs in patients with superficial esophageal squamous cell carcinoma (SESCC).

METHODS

Thirty-five consecutive patients with SESCC were studied for serum p53-Abs by enzyme-linked immunoabsorbent assay before and after treatment. The clinicopathologic features of p53 seropositive and p53 negative patients were compared. The relation between the presence of serum p53-Abs and p53 immunoreactivity of the resected specimens was examined. Three tumor markers (squamous cell carcinoma antigen [SCC-Ag], CYFRA21-1, and carcinoembryonic antigen [CEA]) were assessed to compare their sensitivities with serum p53-Abs.

RESULTS

Fourteen of 35 patients (40%) were p53 seropositive. Relatively few patients tested positive for the other tumor markers: CEA, 11.4%; SCC-Ag, 14.3%; CYFRA21-1, 5.7%. There were no significant correlations between clinicopathologic features and p53 seropositivity except for tumor location. A strong correlation between p53 immunostaining and the presence of serum p53-Abs was observed (P = 0.003). Of the 14 patients with seropositive results, 12 turned seronegative after resection, and the other 2 experienced disease recurrence.

CONCLUSIONS

Surveillance of serum p53-Abs is superior to the three tumor markers for detecting SESCC. This serum marker is also useful for the detection of p53 protein overexpression and for the monitoring of residual tumor cells.