Codon optimization effect on translational efficiency of DNA vaccine in mammalian cells: analysis of plasmid DNA encoding a CTL epitope derived from microorganisms

Interspecific difference of codon usage is one of the major obstacles for effective induction of specific immune responses against bacteria and protozoa by DNA immunization. Using genes encoding major histocompatibility complex class I-restricted cytotoxic T-lymphocyte (CTL) epitopes, derived from an intracellular bacterium, Listeria monocytogenes and a mouse malaria parasite, Plasmodium yoelii, we report here that the codon optimization level of the genes is not precisely proportional to, but does correlate well with the translational efficiency in mammalian cells, which is concomitantly associated with the induction level of specific CTL response in the mouse. These results suggest that DNA immunization using the gene codon-optimized to mammals through the entire region is very effective.

Decreased expression of Th2 type cytokine mRNA contributes to the lack of allergic bronchial inflammation in aged rats

Sensitized Brown Norway rats are known to develop eosinophilic bronchial inflammation and airway hyperresponsiveness after Ag exposure. However, we have previously observed that sensitized aged rats of the same strain failed to develop such allergic inflammation. In the present study, we investigated age-associated changes of cytokine mRNA expression in bronchoalveolar lavage (BAL) cells. Both young (8- to 10-wk-old) and aged (100- to 120-wk-old) Brown Norway rats were sensitized with OVA, and BAL was performed 24 h after OVA inhalation challenge. Semiquantitative RT-PCR analysis of BAL cells showed that the cells from aged rats preferentially expressed Th1 type cytokine (IFN-gamma) mRNA, whereas cells from young animals expressed more Th2 type cytokine mRNAs including those for IL-4 and IL-5. Decreased expression of Th2 type cytokine transcripts in aged animals was further confirmed by quantitative analysis, competitive RT-PCR of BAL cells, and in situ hybridization. The age-associated changes of cytokine profile were not restricted to BAL cells but were a general feature of lymphocytes, as shown by examination of popliteal lymph nodes draining the site of sensitization. These findings suggest that decreased allergic inflammation in aged animals is attributable to age-dependent impairment of Th2 generation in response to Ag.

Case report: A case of lymphoepithelioma-like carcinoma of the oesophagus and review of the literature

A 78-year-old Japanese female was admitted to our hospital with dysphagia and weight loss. An oesophageal tumour was demonstrated radiologically and endoscopically, and was diagnosed as oesophageal cancer by biopsy. Histologically, the resected tumour showed poorly differentiated squamous cell carcinoma with prominent lymphoid stroma and was diagnosed as the so-called lymphoepithelioma-like carcinoma (LELC). Epstein-Barr virus in the tumour was negative by polymerase chain reaction and in situ hybridization. Oesophageal LELC is extremely rare. The cases in the literature, as well as the one reported here, presented with gross features of a submucosal tumour-like appearance. Although the differentiation of the tumour cells is often poor, prognosis seems to be better than for other types of oesophageal cancer. Oesophageal LELC has characteristic clinicopathological features and should be classified by criteria independent of other types of tumour.

The p53 gene mutation is of prognostic value in esophageal squamous cell carcinoma patients in unified stages of curability

BACKGROUND

The p53 gene alteration is identified in approximately half of all human tumors, and is now thought to be a key gene for regulating the cell cycle through the induction of p21(WAF1/CIP1) and inducing apoptosis through some genes such as BAX. In this study, we investigated the prognostic value of p53 mutation for postoperative esophageal squamous cell carcinoma patients.

METHODS

The subjects studied were 42 esophageal squamous cell carcinoma patients who underwent esophagectomy with complete curability in our department. The cases were limited to stage II and III. DNA was extracted from paraffin-embedded tissues. A p53 gene mutation was detected by polymerase chain reaction-single strand conformation polymorphism and subsequent direct sequencing method for exons 5 to 9. The 5-year survival rate was calculated and statistically compared between the p53 mutation(+) and (-) groups by the log rank test.

RESULTS

The p53 gene mutation was identified in 14 cases (33.3%). The 5-year survival rate of the p53 mutation(-) group (n = 28) was significantly higher than the (+) group (n = 14; 51.0% versus 35.7%, P <0.05 by the log rank test). Recurrence could be identified in 10 of 14 p53 mutation(+) cases (71.4%), whereas it was found in 12 of 28 (-) cases (42.8%).

CONCLUSION

The current study indicated that p53 mutation of tumor tissues might be a prognostic factor for esophageal squamous cell carcinoma cases and one of the risk factors for its recurrence.

Expression of wild-type p53 gene confers increased sensitivity to radiation and chemotherapeutic agents in human esophageal carcinoma cells

The status of the p53 gene of tumor cells can modify the sensitivity of the tumors to radiation and anti-cancer agents. Human esophageal cancer cells (T.Tn) bearing mutated p53 gene were retrovirally transduced with wild-type p53 gene. The transduced cells (T.Tn/p53) which stably expressed wild-type p53 proliferated at the same rate as parental cells. However, the sensitivity to radiation was significantly improved by the transduction and T.Tn/p53 cells became markedly susceptible to cisplatin and etoposide compared with parental cells. Administration of cisplatin noticeably suppressed the growth of T.Tn/p53 tumors but not T.Tn tumors inoculated in nude mice. Forced expression of wild-type p53 gene thereby can increase the sensitivity to DNA damage in esophageal cells.

Investigation on SCH00013, a novel cardiotonic agent with Ca++ sensitizing action. 2nd communication: in vivo cardiovascular effects and bioavailability in dogs

In vivo cardiovascular effects and bioavailability of 4,5-dihydro-6-[1-[2-hydroxy-2-(4-cyanophenyl)ethyl]-1,2,5,6- tetrahydropyrido-4-yl]pyridazin-3(2H)-one (SCH00013), a novel cardiotonic agent, were investigated. In anesthetized dogs, intravenous administration of SCH00013 (0.3-10 mg/kg) increased maximum rate of rise in left ventricular pressure (LVdP/dtmax) in a dose-dependent manner with no change in heart rate (HR) and, at the dose of 3 mg/kg or higher, at which the increase in LVdP/dtmax reached the maximum, it decreased blood pressure. In conscious dogs, oral administration of SCH00013 (1-10 mg/kg) also increased LVdP/dtmax dose-dependently with no change in HR. The increase in the plasma concentration of orally administered SCH00013 (3 mg/kg) was parallel to the increase in LVdP/dtmax. The areas under the plasma concentration versus time curve (AUC0-24 h) after oral and intravenous administration of SCH00013 (3 mg/kg) were essentially identical (15.3 +/- 2.0 micrograms.h/ml and 16.5 +/- 2.1 micrograms.h/ml, respectively). These results suggest that oral bioavailability of SCH00013 is notably high. In conclusion, the positive inotropic effect of SCH00013 with neither elevation of HR nor excessive hypotension, as well as the high oral bioavailability of this compound, may provide a beneficial pharmacological treatment of the patients with congestive heart failure.

Lymph node metastasis with adenocarcinoma of the gastric cardia: clinicopathological analysis and indication for D1 dissection

PURPOSE

To establish the indications for proximal resection with dissection of perigastric lymph nodes in order to treat adenocarcinoma of the gastric cardia.

METHODS

We analyzed the clinicopathological features of 110 resected adenocarcinomas of the gastric cardia with respect to the appropriate operative method and extent of lymphadenectomy for treatment.

RESULTS

Of the 110 patients, 93 underwent curative resection. The D2 group (total gastrectomy with dissection of extended regional lymph nodes) revealed higher morbidity and mortality rates compared to the D1 group (proximal resection with dissection of perigastric lymph nodes). The risk of lymph node metastasis was determined by depth of invasion, size of tumors, and gross findings of tumors.

CONCLUSION

The appropriate operative method for adenocarcinoma of the gastric cardia requires: (i) tumor size less than 4 cm; and (ii) gross findings indicating a superficial type of lesion, which are recommended for proximal resection with dissection of perigastric lymph nodes.

Simultaneous Adsorption of Poly(ethylene Oxide) and Cationic Surfactant at the Silica/Water Interface

The simultaneous adsorption of three poly(ethylene oxide) (PEO) with different molecular weights and two cationic surfactants on silica under a constant feed concentration of PEO has been investigated in aqueous solutions. Two cationic surfactants were used; dodecyltrimethylammonium bromide (DTAB) and 1,2-bis(dodecyltrimethyl ammonio) ethane dibromide (2RenQ). The amount of PEO adsorbed decreased with increasing surfactant concentration, while that of the surfactant increased with surfactant concentration but was lower in the presence of PEO than in the absence of PEO, indicating a competitive adsorption. The reduction in PEO adsorption was greater in the presence of 2RenQ than in the presence of DTAB accompanying an increase of the molecular weight of PEO. The dispersion stability of silica suspensions by the competitive adsorption showed a dispersion-flocculation-redispersion sequence with the surfactant concentration, suggesting the importance of electrostatic interactions as well as steric interactions. ESR measurements using spin-labeled PEO show that PEO molecules adsorbed take mainly loops or tails, inducing steric hindrance for the high dispersion stability of silica suspensions. Copyright 1998 Academic Press.

Preparation of a monoclonal antibody specific for human stanniocalcin

Stanniocalcin (STC) is a glycoprotein hormone that was first identified in fish, where it regulates the calcium level in the body fluid. The cDNA which encodes human STC has recently been reported but the function has not been completely elucidated. We have prepared a monoclonal antibody against human STC using an analogous peptide of the putative antigenic domain in human STC; it was conjugated with keyhole limpet hemocyanin (KLH). The monoclonal antibody specifically stained the distal convoluted tubules in human kidney which is a putative target organ of STC. The ELISA was established using the monoclonal antibody and recombinant human STC as a standard antigen. The monoclonal antibody prepared in this study provides a useful tool for clinical studies of STC in human.

Antitumor response of genetically engineered IL-2 expression to human esophageal carcinoma cells in mature T cell-defective condition

We examined whether antitumor effect could be produced by retrovirally expressed human interleukin-2 (hIL-2) gene in human esophageal cancer cells (T.Tn) using immunocompromised nude mice. Loss of tumorigenicity of hIL-2-producing T.Tn (T.Tn/hIL-2) cells inoculated subcutaneously was observed in contrast to continuous tumor growth of wild-type cells, although in vitro proliferation of T.Tn/hIL-2 cells remained the same as that of wild-type cells. The antitumor effect was also evidenced by the injection of T.Tn/hIL-2 cells into established tumors of wild-type cells. The injection significantly retarded the subsequent growth of wild-type tumors. Histological examination of regressing T.Tn/hIL-2 cells revealed necrotic areas and infiltration of several types of inflammatory cells. Treatment of nude mice with anti-asialoGM1 antibody did not influence the IL-2-mediated tumor rejection. Vaccination of nude mice with irradiated T.Tn/hIL-2 cells whose secretion of hIL-2 in amount was comparable to that of unirradiated cells did not develop protective immunity. Taken together, the antitumor effect achieved in nude mice by the inoculation of T.Tn/hIL-2 cells is mediated by non-T non-natural killer cells.

Optimization of codon usage of plasmid DNA vaccine is required for the effective MHC class I-restricted T cell responses against an intracellular bacterium

In an attempt to study codon usage effects of DNA vaccines on the induction of MHC class I-restricted T cell responses against an intracellular bacterium, Listeria monocytogenes, we designed two plasmid DNA vaccines encoding an H-2Kd-restricted epitope of listeriolysin O (LLO) of L. monocytogenes, LLO 91-99. One DNA vaccine, p91wt, carries the wild-type DNA sequence encoding LLO 91-99, and the other one, p91mam, possesses the altered DNA sequence in which the codon usage was optimized for murine system. Our read-through analyses with LLO 91-99/luciferase fusion genes confirmed that the optimized 91mam DNA sequence showed extremely higher translation efficiency than the wild-type sequence in murine cells. Consistent with this, i.m. injections of p91mam, but not of p91wt, into BALB/c mice were capable of inducing specific CTL- and IFN-gamma-producing CD8+ T cells able to confer partial protection against listerial challenge. Taken together, these observations suggest that optimization of codon should be taken into consideration in the construction of DNA vaccines against nonviral pathogens.

Intraoperative management for removal of tumor thrombus in the inferior vena cava or the right atrium with multiplane transesophageal echocardiography

BACKGROUND

To investigate the role and impact of multiplane transesophageal echocardiography during thrombectomy in the inferior vena cava or the right atrium.

EXPERIMENTAL DESIGN

Retrospective.

SETTING

A university hospital.

PARTICIPANTS

Four patients who underwent removal of tumor thrombus in the inferior vena cava (IVC) or the right atrium.

INTERVENTIONS

The medical records of 4 patients and videotapes of these intraoperative transesophageal echocardiography examinations were reviewed.

RESULTS

Before thrombectomy, multiplane transesophageal echocardiography (MTEE) provided excellent IVC long axis view, which offered precise recognition of the cephalic extent of tumor, extent of caval occlusion, characterization of the tumor head. During surgery, MTEE could provide continuous monitoring of cardiac function, cardiac volume, and pulmonary embolism. Moreover, MTEE could provide the useful images of a cannula or the caval occlusion balloon catheter, which facilitated removal of neoplasm extending into the IVC.

CONCLUSIONS

We presented four surgical cases, in which the removal of the tumor extended into the inferior vena cava or the right atrium using MTEE. MTEE could provide valuable information such as excellent images of the tumor, cardiac function, the position of a cannula or the caval occlusion balloon catheter. These findings could improve the anesthetic management of the patients, as well as the surgical approach and technical maneuvers, and facilitate removal of neoplasm into the IVC.

Reduced susceptibility to collagen-induced arthritis in mice deficient in IFN-gamma receptor

Collagen-induced arthritis (CIA) is an arthritic model that was developed after immunization with type II collagen (CII). Apparently, contradictory results have been reported regarding the role of IFN-gamma in the development of CIA. Therefore, we employed IFN-gamma R-deficient mice to study the role of IFN-gamma. To introduce the CIA susceptibility gene (H-2q), IFN-gamma R-deficient (H-2b/b/IFN-gamma R-/-) mice were mated with DBA/1 (H-2q/q/IFN-gamma R+/+) mice; next, the F1 mice were interbred to yield F2 offspring bearing different combinations of H-2 (H-2q/q, H-2q/b, and H-2b/b) and IFN-gamma R (IFN-gamma R+/+, IFN-gamma R+/-, and IFN-gamma R-/-) genes. Although the H-2q allele appeared to confer susceptibility to CIA, mice that were homozygous for the IFN-gamma R mutation showed a substantially decreased incidence and severity of CIA. The CII-specific IgG levels of serum samples, which are known to be involved in the development of CIA, were remarkably reduced in IFN-gamma R-/- mice. Furthermore, the anti-CII IgG2a levels controlled by IFN-gamma R were significantly reduced in IFN-gamma R-/- F2 mice compared with those seen in IFN-gamma R+/+ and IFN-gamma R+/- mice, although the levels of all IgG subclass Abs examined were lower in IFN-gamma R-/- mice than in IFN-gamma R+/+ mice. No clear evidence of the imbalance of Th1/Th2 cytokines was observed in CII-immunized, IFN-gamma R-deficient mice. Taken together, these results suggest that IFN-gamma exacerbates CIA by affecting, at least, levels of CII-specific IgG Ab rather than the imbalance of Th1/Th2 cells.

Detection of serum p53 antibodies in patients with esophageal squamous cell carcinoma: correlation with clinicopathologic features and tumor markers

The significance of serum p53-Abs in patients with esophageal squamous cell carcinoma was determined. Examination of clinicopathological features and assessment of tumor marker sensitivities of carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC-Ag) and CYFRA21-1 were performed. Thirty-three (58%) of 57 patients were positive for serum p53-Abs, however, no relation with cancer progression existed. Fourteen of the 33 sero-positive patients revealed normal levels of all tumor markers tested. Thus, serum p53-Abs appears to be a useful marker for the detection of esophageal squamous cell carcinoma.

Benign esophageal stricture caused by diffuse severe esophagitis presenting as ascending fibrosis: report of a case

A 46-year-old Japanese man was referred to our hospital for treatment of an esophageal stricture. Esophageal cancer was suspected after detailed investigations, and a right transthoracic esophagectomy was performed. The resected specimen showed only nonspecific esophagitis with severe fibrous thickening in the submucosa, but no evidence of malignancy. Between 1906 and 1993, only 19 similar cases of benign esophageal strictures with fibrous thickening, excluding congenital and iatrogenic strictures, have been reported in Japan. These lesions occurred in the middle to lower third of the esophagus in 15 of 19 cases (78.9%), and 8 of the 19 patients (42.1%) were aged between 30 and 50 years. The interval between onset and hospital admission was short, being less than 1 year in 8 of the 12 patients for whom this information was available. Our patient demonstrated a disorder resembling the diffuse severe esophagitis described by Roth in 1974.

Heart rate variability during the first month of smoking cessation

BACKGROUND

Heart rate variability (HRV) is known to increase after smoking cessation. However, no work has been performed concerning HRV immediately after smoking cessation.

METHODS AND RESULTS

We studied HRV before and from 1 day to 1 month after smoking cessation and also determined whether there is a relation between HRV and the withdrawal syndrome immediately after smoking cessation. We determined HRV by using a two-channel 24-hour ambulatory ECG system before and 1, 2, 3, 7, 14, 21, and 28 days after smoking cessation in 20 healthy male volunteers who had smoked one or more packs per day for 2 or more years. One day after smoking cessation, heart rate decreased significantly, and all 24-hour time and frequency domain indices of HRV increased except the standard deviations of the normal R-R intervals and the 5-minute mean R-R. The magnitude of increase in these indices peaked 2 to 7 days after smoking cessation and gradually decreased thereafter. The increase in HRV persisted 1 month after smoking cessation. In the 16 subjects with signs of withdrawal syndrome and in the four subjects without evidence of withdrawal before and immediately and 1 month after smoking cessation, HRV increased immediately after smoking cessation and remained elevated after 1 month.

CONCLUSIONS

HRV increases immediately after smoking cessation and gradually declines thereafter, which suggests that the effect of smoking on autonomic activity rapidly disappears immediately after smoking cessation. HRV remained unaffected by the presence or absence of the withdrawal syndrome.

Evaluation of esophageal cancers using fluorine-18-fluorodeoxyglucose PET

To evaluate glucose metabolism in esophageal cancer, 48 patients were studied using PET with 18F-2-fluoro-2-deoxy-D-glucose (FDG).

METHODS

After transmission scans were obtained, 18F-FDG (148 MBq) was administered intravenously. In 11 patients, a dynamic study was performed to evaluate glucose metabolism. Using the changes of radioactivity in both plasma and tumor, rate constants (k1-k4) defined in the metabolic model for 18F-FDG were calculated. In 48 patients, static PET scans of the tumor (5-min scans) were obtained 60 min after administration. Fluorine-18-FDG activity within each tumor was corrected for physical decay and normalized by dose administration and patient weight to produce a standardized uptake value (SUV).

RESULTS

Both the k3 value (n = 11) reflecting hexokinase activity and SUV (n = 13) were well correlated with hexokinase activity from the resected specimen (p < 0.05). Forty-seven of 48 patients before treatment revealed SUV greater than 2.0, but 10 normal control subjects and 1 esophageal benign tumor revealed less than 2.0 (accuracy rate 98.3%). Although clinicopathological findings did not correlate with SUV, except for two patients with carcinosarcoma, 23 patients with an SUV greater than 7.0 had a poor prognosis compared with 25 patients with SUVs less than 7.0.

CONCLUSION

These findings suggest that 18F-FDG PET may be useful in distinguishing malignant tumors from benign lesions and in the preoperative evaluation of the prognostic factor.

ATP-induced ventricular asystole and hypotension during endovascular stenting surgery

PURPOSE

To describe four cases of endoluminal stenting surgery in which adenosine 5'-triphosphate (ATP) was used to arrest the heart for accurate placement of the stent-graft.

CLINICAL FEATURES

Four patients with descending thoracic aortic aneurysm were anaesthetized for deployment of a self-expanding stent-graft. Maintenance of general anaesthesia was performed with isoflurane and nitrous oxide in three patients, and with fentanyl and propofol in another. An initial trial of 20 mg ATP was administered via a central venous catheter as rapidly as possible, and produced third degree AV block of 8 +/- 1.7 sec and 59.7 +/- 17.5 sec hypotension, mean blood pressure < 60 mmHg, in three patients. The time to onset of AV block was 15.7 +/- 6.7 sec. In these patients, deployment of the stent-graft was performed during ventricular asystole produced by 30 mg ATP, which produced 16.3 +/- 2.1 sec third and second degree AV block. In one patient anaesthetized with fentanyl and propofol, 20 mg ATP did not change AV conduction. However, after 10 mg edrophonium, 20 mg ATP produced 9 sec third degree AV block. In all cases, heart rate and PQ interval were restored to the pre-drug control level within 50 sec after the commencement of AV block. There were no clinical complications related to this procedure in any patient.

CONCLUSION

ATP is a convenient and suitable agent to produce transient ventricular asystole for the precise deployment of a self-expanding stent-graft. Co-administration of a parasympathomimetic agent might potentiate the inhibitory effect of ATP on AV conduction.

Prognosis following acute myocardial infarction in patients with ECG evidence of left ventricular hypertrophy prior to infarction

This study was designed to determine the relationship between prognosis after myocardial infarction (MI) and left ventricular hypertrophy (LVH). Left ventricular hypertrophy diagnosed by electrocardiography according to the criteria of Sokolow and Lyon was noted in 57 of 223 patients (25.6%) on the pre-MI electrocardiogram (ECG), in 11.2% on an early post-MI ECG, and in 11.3% on the discharge ECG. In-hospital and 1-year postdischarge mortalities were significantly greater in patients with LVH noted on pre-MI ECG than in patients without prior LVH. There was no relationship between the presence of LVH on early post-MI ECGs and in-hospital or postdischarge 1-year mortality. Multivariate analysis revealed that evidence of LVH on a pre-MI ECG and acute congestive heart failure were independent predictors of cardiac death within 1 year of MI in patients over 70 years old. It is concluded that in patients over 70 years of age, the presence of LVH on a pre-MI ECG is a reliable predictor of post-MI prognosis.

Induction of antitumor effect on human esophageal carcinoma cells by the retroviral expression of granulocyte macrophage-colony stimulating factor gene

We have examined antitumor effect of human esophageal carcinoma cells (T.Tn) which were retrovirally transduced to express mouse granulocyte macrophage-colony stimulating factor (mGM-CSF) gene. Nude mice inoculated with T.Tn cells secreting mGM-CSF developed small tumors but the tumors regressed spontaneously, although the proliferation in vitro of transduced cells was not different from that of wild-type cells. In contrast, the tumor of T.Tn cells transduced with human GM-CSF grew as that of wild-type cells, since murine GM-CSF receptors do not bind to human GM-CSF. Histological examination of the regressing tumor of mGM-CSF-producing T.Tn cells revealed predominant infiltration of inflammatory cells including macrophages. In addition, local injection of mGM-CSF-producing T.Tn cells into the established wild-type tumors significantly induced the retardation of subsequent wild-type tumor growth, suggesting that T-cell independent local response plays a crucial role in destroying tumor cells.

Expression of p53 and p21WAF1/CIP1 proteins in gastric and esophageal cancers: comparison with mutations of the p53 gene

The p53 gene has been shown to be commonly mutated in various human cancers, and mutant p53 can act as a dominant oncogene. The intact p53 protein is also known to induce the cyclin-dependent kinase inhibitor p21WAF1/CIP1 and is implicated in cell cycle arrest. We investigated p53 gene alterations in gastric adenocarcinoma and esophageal squamous cell carcinoma to elucidate the association of the nuclear accumulation of the p53 protein and/or p21WAF1/CIP1 protein. Abnormalities of the tumor suppressor gene p53 protein and the expression of p21WAF1/CIP1 protein were analyzed by immunohistochemical techniques in 32 cases of gastric adenocarcinoma and 15 cases of esophageal squamous cell carcinoma. Twenty cases of gastric cancer and five cases of esophageal cancer were also analyzed for p53 gene mutation by polymerase chain reaction and direct nucleotide sequencing. Overexpression of p53 protein was found in 13/32 (41%) of gastric cancers and 5/15 (33%) of esophageal cancers. We found immunodetectable p53 in 10/14 cases with mutations and in none of 11 cases without mutations in gastric and esophageal cancers. Hence, immunohistochemical and genetic analyses gave concordant results in 84% of 25 cases, revealing a good correlation between immunostaining of p53 and missense mutation of the p53 gene. p53 immunostaining was not observed in cases with frameshift or splicing mutation. The expression of p21WAF1/CIP1 protein was found in 9/32 (29%) of gastric cancers and 4/15 (27%) of esophageal cancers and in 2/14 (14%) cases with alteration of the p53 gene and in 5/11 (45%) without. These results suggest that abnormalities of p53 may be closely associated with the pathogenesis of gastric adenocarcinoma and esophageal squamous cell carcinoma and that the immunoreactivity of p53 protein is a general indicator of the tumors with altered p53 function. The expression of p21WAF1/CIP1 protein was suppressed in the neoplastic tissues with and without p53 gene alteration.