Clinical usefulness of serum antip53 antibodies for prostate cancer detection: a comparative study with prostate specific antigen parameters

PURPOSE: Alterations in the p53 tumor suppressor gene located on human chromosome 17p13.1 are currently the most common genetic abnormalities associated with many different types of human malignancies. Recently serum p53 antibodies (p53-Abs) have been detected in the serum of patients with various cancers. To evaluate the clinical usefulness of serum p53-Abs we compared p53-Abs with prostate specific antigen (PSA) parameters in patients with benign prostatic disease (BPD) and prostate cancer. MATERIALS AND METHODS: Serum samples were obtained from 50 patients with BPD and 103 with histologically diagnosed prostate cancer, including T1c/2N0M0 in 50, T3N0M0 in 29 and TxNxM1 in 24. The serum p53-Abs titer was assessed by enzyme-linked immunoabsorbent assay using a MESCUP Kit II (Medical and Biological Laboratories Co., Ltd., Nagoya, Japan) antip53 test. Free and total PSA was measured using an Architect (Dinabott, Chicago, Illinois) PSA kit. The clinical values of p53-Abs were compared with total PSA, PSA density (PSAD), PSA density of the transition zone (PSATZD) and the free-to-total PSA ratio using ROC curves. RESULTS: All patients with prostate cancer had significantly higher total PSA, PSAD, PSATZD and p53-Abs than patients with BPD. While total PSA, PSAD, PSATZD and free-to-total PSA ratios were associated with stage progression, serum p53-Abs were not related to clinical stage. The Gleason sum 5 or less group had a higher level of p53-Abs than higher Gleason sum groups. Patients with T1c cancer had significantly higher p53-Abs than those with BPD. According to ROC curve analysis to distinguish prostate cancer from BPD the p53-Abs titer had the greatest AUC in the overall patient population and in patients without digital rectal examination findings. CONCLUSIONS: These results suggest that p53-Abs might be helpful in the clinical decision to perform prostate biopsy. In the current study the serum p53-Abs titer had the most useful validity in discriminating between prostate cancer and BPD in the overall patient population and in patients with normal digital rectal examination.     

p53 antibodies in the serum of patients with prostate cancer

We assessed the potential clinical utility of levels of p53-specific antibodies as a novel serum biomarker of prostate cancer that could be used in conjunction with level of PSA. Material and methods Serum levels of p53-specific antibodies in patients with relapsed, newly diagnosed prostate cancer and in patients with benign prostate hyperplasia were quantified by an enzyme-linked immunoabsorbent assay. Result There was no significant difference (P = 0.96) between the serum levels of p53-specific antibodies in patients with newly diagnosed prostate cancer and with benign prostatic hyperplasia. In the newly diagnosed prostate cancer group, stage T1c (n = 8) showed the lowest p53-specific antibody level. However, the difference between T1c group and benign prostatic hyperplasia group was not significant (P = 0.686). The relapsed cancer group tended to have low levels of the antibodies, and, there was no significant difference between the relapsed prostate cancer group and the benign prostatic hyperplasia group (P = 0.14). The serum levels of p53-specific antibodies in patients with metastatic and with localized prostate cancer showed no significant difference (P = 0.68). Conclusion The use of titers of p53-specific antibodies to make differential diagnosis between prostate cancer and benign prostatic hyperplasia might have no role, and the antibodies should not be used as a marker of prostate cancer by itself. Because our study is based on small number of patients, further studies are necessary before its absolute validity can be determined.     

Association of positive serum anti-p53 antibodies with poor prognosis in bladder cancer patients

AIMS: To assess the association of serum anti-p53 antibodies and overexpression of tumor p53 protein with survival and prognostic factors in patients with urinary bladder tumors. METHODS: Seventy-six patients with transitional cell carcinoma of the urinary bladder were assessed prospectively (Ta, 18; T(1), 30; > or =T(2), 28). Serum anti-p53 antibodies were detected by enzyme-linked immunosorbent assay. Tumor p53 gene overexpression was assessed by immunohistochemical staining. The mean follow-up time was 34 months. RESULTS: Serum anti-p53 antibodies were positive in 25 patients (33%). Overexpression of tumor p53 protein was positive in 41 patients (54%). There was an association between the presence of serum anti-p53 antibodies and tumor p53 gene overexpression (P = 0.001). The total survival of the patients with positive serum anti-p53 antibodies was shorter than the patients with positive tumor p53 gene overexpression (P < 0.001, P = 0.344, respectively). In the multivariate survival analysis, both tumor stage and serum-p53 antibodies were found to be independent survival predictors (P = 0.004, P = 0.006, respectively). CONCLUSION: Serum anti-p53 antibody positive tumors had a worse prognosis than those with negative serum levels, regardless of the p53 status of the tumor.     

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. This work was supported in part by a Grant-in-Aid from the Ministry of Education, Science and Culture of Japan (21st Century Center of Excellence Program).     

Preclinical study of adenoviral p53 gene therapy for esophageal cancer

An alteration of the p53 gene function is a major factor in the development of esophageal cancer. Recently, p53 gene therapy has been applied for clinical studies in lung cancer and head and neck cancer. However, no preclinical studies have yet demonstrated an anticancer effect of adenoviral-mediated wild-type p53 gene therapy on esophageal cancer. We herein evaluated the effect of p53 adenoviral gene therapy on human esophageal squamous cell carcinoma to test the ability of clinical application. A normal esophageal epithelial cell line (EN53F) and two human esophageal cancer cell lines (ECGI-10 and T.Tn) with a p53 alteration were used. The transduction efficiency, p53 protein expression, p21 protein expression, the induction of apoptosis, and growth suppression were assessed by using the recombinant adenoviral vector Ad5CMV-p53. The transduction efficiency was 60%–80% at 100 plaque-forming units (PFU)/cell and 80%–100% at 300 PFU/cell. A significant growth suppression following an Ad5CMV-p53 infection was observed in both cancer cell lines. A Western blot analysis confirmed the presence of both exogenous p53 protein expression and p21 protein induction. Apoptotic cell death was observed with TUNEL staining. T.Tn xenografts in nude mice transduced with Ad5CMV-p53 demonstrated significant growth suppression. These data suggest that Ad5CMV-p53 may thus be a potentially effective therapeutic agent for locally advanced esophageal cancer. Received: July 19, 2000 / Accepted: January 9, 2001     

结直肠癌患者血清p53抗体与肿瘤p53蛋白表达关系的研究

目的　探讨结直肠癌患者血清p5 3抗体与肿瘤组织p5 3蛋白表达的关系 ,评价其能否间接反映p5 3基因的突变。方法　对 13 2例手术治疗的结直肠腺癌患者和 3 6例非肿瘤患者进行血清p5 3抗体定性检测。结直肠癌标本行p5 3蛋白免疫组化染色。结果　结直肠癌组中 5 3例 (4 0 .2 % )血清p5 3抗体阳性 ,而对照组仅 1例 (2 .9% )阳性 (P <0 .0 1)。在 75例p5 3蛋白染色阳性者中 5 1例 (68.0 % )血清p5 3抗体阳性 ;而 5 7例p5 3蛋白染色阴性的患者中 ,仅 2例 (3 .5 % )血清p5 3抗体阳性。结直肠癌血清p5 3抗体阳性率与肿瘤组织p5 3蛋白免疫组化染色阳性反应有明显关系 (P<0 .0 1)。结论　血清p5 3抗体能反映结直肠癌p5 3蛋白的阳性表达 ;检测血清p5 3抗体是间接判定P5 3基因突变的一种可靠而简便的方法。     

p53 overexpression and K-ras gene mutations in primary sclerosing cholangitis-associated biliary tract cancer

Cholangiocarcinoma occurs frequently in patients with primary sclerosing cholangitis (PSC). We evaluated the incidence and prognostic significance of p53 protein overexpression and K-ras gene mutations in patients with biliary tract cancer and PSC. p53 protein expression was determined in specimens from 12 patients with biliary tract cancer, using the antibody, D07. K-ras mutations were detected using DNA sequencing and a mutation ligation assay. Accumulation of p53 protein was detected in 6 of 12 tumors (50%). K-ras mutations were detected in 4 of 12 tumors (33%). Overall survival in patients with p53-negative tumors was significantly longer (P < 0.05) than that in patients with p53-positive (mutant) tumors. Similarly, overall survival was significantly longer (P < 0.05) in the absence of a K-ras mutation than in patients with a tumor containing a K-ras mutation. Mean interval from the time of diagnosis of PSC until the diagnosis of biliary tract cancer was significantly shorter (P < 0.05) in patients with p53 overexpression than in those patients without p53 overexpression (2 versus 47 months). p53 overexpression and K-ras mutations occur commonly in patients with PSC and biliary tract cancer and are associated with a shortened survival. Patients with longstanding PSC are less likely to have these genetic alterations and may have a better prognosis. Received: September 24, 1999 / Accepted: June 6, 2000     

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.     

Expression of p53 protein related to human papillomavirus and DNA ploidy in superficial esophageal carcinoma

We examined the p53 protein and human papilloma virus (HPV) by immunohistochemistry and DNA ploidy by cytofluorometry in paraffin-embedded esophageal carcinoma tissue specimens. Sixty-one patients with superficial esophageal carcinoma were operated on between 1983 and 1991 without any prior treatment. Immunostaining of the anti-p53 protein antibody (CM1) was positive in 32 carcinomas (52%). Patients with p53-positive tumors had a poorer outcome than those with p53-negative tumors (P<0.05). In addition, patients with p53-positive tumors did not have any characteristic site of relapse. Only 5 of the 61 patients (8.2%) had HPV-positive tumors. One of these 5 carcinomas expressed both p53 protein and HPV. Three patients with HPV-positive tumors which had invaded the submucosal layer died of relapse. A determination of DNA ploidy revealed 30 patients with aneuploid tumors, 13 with polyploid tumors and 18 with diploid tumors. The outcome of the patients with aneuploid tumors was worse than that of the patients with diploid tumor (P<0.05). p53 protein expression was not associated with DNA ploidy; however, the 16 patients who had both p53-positive and aneuploid tumors had a worse prognosis than patients with p53-negative and aneuploid tumors (P<0.01). These findings suggest that p53 protein expression in conjunction with DNA ploidy may be a useful indicator in evaluating the prognosis of patients with superficial esophageal carcinoma.     

Serum p53 and bladder cancer: can serum p53 be used as a tumor marker?

The aim of this study was to find the correlation between serum p53 and carcinoma of the bladder and to investigate whether serum p53 protein can be used as a tumor marker for p53 gene alteration. The study included patients with carcinoma of the bladder and controls. Serum p53 protein estimation was done with an ELISA kit. There were 23 patients with superficial and 17 with invasive carcinoma. The median serum p53 was 31.5 U/ml in superficial and 41 U/ml in invasive cancer. This was significantly higher than the mean value (16.4 U/ml) of controls. Serum p53 rises in patients with carcinoma of the bladder and correlates with the grade of the disease .It can therefore be used as a tumor marker for bladder cancer.     

Analysis of the Survival Period in Resectable Stage IV Gastric Cancer

Background: Patients with stage IV gastric cancer usually have a poor prognosis, but some patients with resectable cancer survive for more than 5 years. We aimed to study the correlation of protein expression and survival in resectable stage IV gastric cancer.Patients and Methods: Tissue samples of 42 patients with resectable stage IV gastric cancer were stained immunohistochemically for the mutant p53 protein and heat shock protein-27 (hsp27). The correlation between protein expression and clinicopathological factors was investigated. Furthermore, prognostic value of each factor was analyzed.Results: Univariate analysis showed that pN factors (Japanese classification, P = .028; International Union Against Cancer classification, P = .024), blood vessel invasion (P = .043), hsp27 overexpression (P = .019), and the index of p53 and hsp27 overexpression (P = .0026) had a prognostic influence. Only Lauren classification, however, revealed the prognostic influence in multivariate analysis (P = .046).Conclusions: These results suggest that immunostaining of tumor specimens for p53 and hsp27 and clinicopathological analysis may help predict the survival of patients with resectable stage IV gastric cancer.     

P53 Overexpression and Proliferative Potential in Malignant Meningiomas

Summary  Meningiomas are generally benign, but some meningiomas show malignancy with invasion and high recurrence rates. We investigated whether alterations in p53 protein may contribute to malignant progression in meningiomas. Immunostaining for p53 protein was performed on paraffin and frozen sections from 61 patients with different grades of meningiomas using monoclonal antibodies (mAbs) DO-1 and pAb240. Immunoblot analysis was performed to quantitate the amount of p53 protein. Mutations in p53 genes were assessed by single-strand conformational polymorphism (SSCP) analysis. MIB-1 immunostaining was used to detect proliferative potentials of meningiomas. We found an overexpression of p53 protein in all of five cases of anaplastic meningiomas by immunohistochemistry using DO-1 mAb. No p53 positive cells were recognized in atypical meningiomas, and several cells were weakly stained in only two of 52 benign meningiomas.  p53 staining index and immunoblot analysis indicated increasing amounts of p53 protein associated with subsequent recurrences of anaplastic meningiomas. The MIB-1 staining index was positively correlated with tumour grade and p53 protein overexpression. Immunostaining of frozen sections using the mutant-specific mAb pAb240, as well as mutation gene analysis by SSCP, indicate that the overexpressed p53 protein is not a mutant- but wild-type p53 protein. Four atypical meningiomas did not recur after surgical removal and radiation, while 4 anaplastic meningiomas with overexpressed p53 protein recurred repeatedly at short intervals even after radiation. Our results suggest that accumulation of p53 protein associated with highly proliferative potentials is a common and characteristic feature that may indicate malignant biological behaviour in meningiomas.     

Long-term monitoring of serum p53 antibody after neoadjuvant chemotherapy and surgery for esophageal adenocarcinoma: report of a case

We monitored serum p53 antibody (s-p53-Ab) titers in a 76-year-old man with esophageal adenocarcinoma, clinical stage III (T2N2M0), for over 4 years, including during the perioperative period and throughout follow-up after surgery. Screening tests for CA19-9 (205 IU/ml) and s-p53-Abs (381 U/ml) were positive before treatment. After neoadjuvant chemotherapy with 5-FU and cisplatin, CA19-9 decreased to the normal range, but the s-p53-Ab titer remained positive (224 U/ml). Pathological findings of surgically resected specimens showed stage T1b disease and no lymph node metastases. After surgery, s-p53-Ab titers consistently decreased, with no disease recurrence. Although the s-p53-Ab titer remained positive even after 4 years, it decreased to 8.66, 3.59, 2.38, and 1.92 U/ml, 1, 2, 3, and 4 years after surgery, respectively. Thus, monitoring perioperative changes in s-p53-Ab titers proved useful for detecting the presence of residual cancer cells in a patient with superficial esophageal adenocarcinoma.     

MDM2/p53 protein expression in the development of colorectal adenocarcinoma

The murine double minutes 2 (MDM2) oncoprotein inhibits p53-mediated tumor suppression. MDM2 has been shown to be overexpressed in sarcomas and more recently was implicated in the pathogenesis of carcinomas. The purpose of this study was to determine the expression pattern of MDM2 in adenomas and colorectal adenocarcinomas and decide whether there is a correlation between MDM2 and p53 protein status. Paraffin-embedded tissues from 52 colorectal cancer (CRC) specimens and their adjacent normal tissue (N-CRC) were studied. In addition, 56 sporadic adenomas were investigated for the immunohistochemical expression of MDM2 and p53 proteins. Immunoreactivity of p53 indicating p53 gene mutation (p53 +) was significantly higher in CRC (44%) compared to adenomas (23.2%) (P <0.01). None of the N-CRC specimens expressed the immunoreactive p53 protein. MDM2 overexpression (MDM2+) was similar in adenomas (30.3%) and CRC (25%), but only 2 (3.8%) of 52 N-CRC specimens showed overexpression of MDM2. In most cases MDM2 expression was associated with negative p53 expression (wild-type p53) in both adenomas (r = 0.59, P <0.001) and CRC (r = 0.69, P <0.0001). No correlation was found between MDM2, p53 expression, and either the histologic grade, nodal stage or morphology of the tumors. There is greater p53 mutation in CRC compared to adenomas and N-CRC. The data indicate that MDM2 is overexpressed in CRC and is significantly associated with wild-type p53 compared to N-CRC specimens from the same patient. The MDM2 expression pattern is similar in adenomas and CRC, which may suggest that MDM2 overexpression is an early event in the progression of CRC. Supported by a grant from The Methodist Hospital Foundation, Houston, Tex. Presented at the Fortieth Annual Meeting of The Society for Surgery of the Alimentary Tract, Orlando, Fla., May 16–19, 1999.     

Relation between serum anti-p53 antibodies and microvessel density in bladder cancer patients

INTRODUCTION: Etiology of serum anti-p53 antibodies in bladder cancer patients is still unknown. In this study we evaluated the relationship between serum anti-p53 antibodies and microvessel density in bladder cancer patients. MATERIALS AND METHODS: Seventy-six patients with transitional cell carcinoma of the urinary bladder were assessed prospectively (18 Ta, 30 T1, 28 T2>or =). Serum anti-p53 antibodies were detected by enzyme-linked immunosorbent assay. Tumor p53 overexpression was assessed by immunohistochemical staining. Vessels were stained immunohistochemically using an antibody against platelet endothelial cell-adhesion molecule CD31. Spearman correlation test and t test were used for statistical analysis. RESULTS: Serum anti-p53 antibodies were positive in 25 (60%) of 41 tumor p53-positive patients. While the mean (SD, range) microvessel density was found to be 43 (7.59, 8-99) in patients who had positive serum anti-p53 antibodies, it was found to be 23 (4.53, 6-98) in patients who had negative serum anti-p53 antibodies. There was a good correlation between serum anti-p53 antibodies and microvessel density (p<0.05). No correlation was found between tumor p53 expression and microvessel density (p>0.05). CONCLUSIONS: We found that there is a significant correlation between the microvessel density and serum anti-p53 antibodies. This result may show the role of angiogenesis in the etiology of serum anti-p53 antibodies in bladder cancer patients.     

食管癌发生发展过程中p53蛋白表达的研究

目的研究p53蛋白在食管癌及癌前病变组织中的表达,探讨其在食管癌发生、发展过程中的作用。方法应用免疫组织化学方法检测43例鳞状细胞癌及22例增生性病变(单纯性增生8例,轻、中、重度不典型增生分别为6例、4例、4例)和6例正常食管黏膜鳞状上皮的食管组织中p53蛋白的表达情况。结果在正常食管黏膜上皮,单纯性增生,轻、中度不典型增生中,未发现p53蛋白的表达;在75%(3/4)重度不典型增生、56%(24/43)食管鳞状细胞癌中p53蛋白表达阳性。p53蛋白表达在I～II期为18%(2/11),III～IV期为77%(10/13)。p53蛋白表达,与淋巴转移、浸润深度、肿物大小无关。结论 p53蛋白的表达与食管癌发生发展关系密切,是食管癌发生发展中的一个重要指标。可作为食管癌可疑病例定期随访的指标之一,以便发现早期食管癌,做到早诊断早治疗。     

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.

     

Relation between K-ras codon 12 mutation and p53 protein overexpression in gallbladder cancer and biliary ductal epithelia in patients with pancreaticobiliary maljunction

It is well known that the incidence of biliary cancer is higher in patients with pancreaticobiliary maljunction (PBM) than in individuals without PBM. However, the relationship between PBM and the carcinogenesis remains unclear. The purpose of the present study was to examine histopathologic changes in the mucosa of the gallbladder and bile duct in patients with PBM, and to investigate K-ras oncogene mutation and overexpression of p53 protein in the mucosa. We examined 47 surgical specimens of gallbladder and 36 surgical specimens of bile duct obtained from 48 patients with PBM. The 48 patients were divided into three age groups: group A (0–3 years), group B (4–39 years), and group C (40 years or more). Investigation of K-ras mutation and overexpression of p53 protein was performed using an enriched polymerase chain reaction (PCR) and enzyme-linked mini-sequence assay (ELMA), and by the streptavidin-biotin (SAB) method, using DO-7 antibodies, respectively. Hyperplastic changes in the gallbladder mucosa were observed in patients in the three groups. However, metaplastic or dysplastic changes were observed in the mucosa of only groups B and C. K-ras gene mutation in the gallbladder mucosa was found in 18.8% of the hyperplastic mucosae in group B and in 20% in group C. The mutation was found in 33.3% of lesions with metaplastic change associated with hyperplastic changes and in 25% of lesions with dysplastic changes in group C. No mutation was observed in the non-cancerous mucosae of gallbladders and bile ducts without congenital dilatation of the bile duct. Overexpression of p53 protein was observed only in carcinoma of the gallbladder; in seven of nine advanced carcinomas and in two of three carcinomas in situ. We concluded that the mucosal epithelia of the biliary system in patients with PBM showed a high frequency of gene mutations and the carcinogenesis appeared in involve a multistage process of mutation in the K-ras gene and the p53 supressor gene. Received for publication on Feb. 3, 1999; accepted on Oct. 18, 1999     

Prediction of 5-Fluorouracil and Cisplatin Synergism for Advanced Gastrointestinal Cancers Using a Collagen Gel Droplet Embedded Culture

Purpose. The combination effects of 5-fluorouracil (5-FU) and cisplatin (CDDP) are herein reported using a drug sensitivity assay, with a special focus on the induction of apoptosis.Methods. The combination effects of 5-FU and CDDP were examined using in vitro chemosensitivity testing by means of the collagen gel droplet embedded culture drug sensitivity test (CD-DST) in MKN45 and GSS cell lines, and primary gastrointestinal cancer cells ob-tained from 40 patients. Apoptosis was assayed using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin neck end labeling (TUNEL) method.Results. The combination of 5-FU with CDDP increased the efficacy of 5-FU 1.16–1.35-fold with the GSS cell line and 1.10–2.01-fold with primary gastric and colorectal cancers when the exposure time was 7 days. In primary tumor cells a synergistic action was noted in 15 of 40 (38%) gastric and colorectal cancers. Both 5-FU and CDDP were found to induce apoptosis in GSS and MKN45 cells, and the number of apoptotic cells increased synergistically after the combined treatment in the GSS cases and showed a correlation with the results of CD-DST.Conclusions. Our findings suggested that the efficacy of the combined treatment with 5-FU and CDDP can be predicted by the in vitro chemosensitivity test and that a synergistic effect might be associated with the induction of apoptosis.     

P-170 Glycoprotein (MDR) and p53 Expression in Breast Cancer

An immunohistochemical comparative analysis of P-170 glycoprotein and p53 was performed in 37 breast cancer patients who underwent curative resection without preoperative chemotherapy. The antibodies utilized were C-219 and JSB-1 for P-gp and DO-7 for p53. Positive cytoplasmic and membrance positivity for P-gp was found in 22 (59.45%) of the 37 tumor specimens. In comparing tissue immunoreactivity by the specific antibodies, 15 (40.54%) samples showed immunostaining for C-219, 12 (32.43%) for JSB-1, and 5 (23%) for both. P-gp expression was not statistically related with the clinicopathological variables analyzed, that is, age, TNM stage, histologic type, lymph node involvement, tumor diameter, and hormone receptor status. p53 overexpression was observed in 22 (59.45%) of the 37 tumor samples analyzed. There was a significant correlation between p53 overexpression and P-gp positive immunostaining (p = .007). p53 was also significantly correlated with TNM stage (p < .05) and lymph node involvement (p < .02). Our results demonstrated that the three distinct patterns of reactivity with the two antibodies result from the combined expression of each of the three P-gp isoforms. An immunohistochemical analysis with different antibodies may be used to determine and correlate the expression pattern of P-gp isoforms with response to chemotherapy.