Clinical significance of MT1-MMP mRNA expression in breast cancer

Membrane-type 1 matrix metalloproteinase (MT1-MMP) is known as an activator of MMP-2. We reported that the expression of MT1-MMP is a powerful indicator of lymph node metastasis in gastric cancers. We now examined the possibility that MT1-MMP expression also is an indicator of lymph node metastasis in breast cancer. We examined the clinicopathologic significance of the expression of MT1-MMP mRNA in 53 breast cancer specimens by the semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) assay. The highest expression of MT1-MMP was found in those specimens showing lymph node metastasis and/or lymph vessel invasion. Therefore, an analysis of MT1-MMP can predict the presence of lymph node metastasis in breast cancer patients by RT-PCR assay in minute amounts of tissue. We believe this is an objective assay for determining the role of MT1-MMP for metastasis in patients with breast cancer.

Mutation analysis of hBUB1, human mitotic checkpoint gene in multiple carcinomas

hBUB1 is a human homolog of yeast mitotic check point gene that plays an important role in chromosome segregation. Recently mutations of hBUB1 were reported in colorectal cancer cell lines, indicating that inactivation of this gene could be directly involved in aneuploidy in human carcinoma cells. To obtain information of the magnitude of hBUB1 inactivation in multiple carcinomas, we examined mutations in 59 multiple carcinoma cell lines showing single base alteration, however, there was no mutation of hBUB1 with amino acid change in these carcinomas. There were four silent mutations at codon 93, codon 735, codon 430 and codon 98 in KYSE190, TE8 esophageal carcinoma cells, KATOIII gastric carcinoma cells and 697 B cell leukemia cells, respectively. Two candidates of mutation were identified in TE3 esophageal carcinoma cells and 697 B cell leukemia cell line at codon 9 and codon 285, respectively. This result suggests that the inactivation of hBUB1 may be very rare in human carcinomas, or restricted to certain cell lines of colorectal carcinomas.

Second cancers after adjuvant tamoxifen therapy for breast cancer in Japan

BACKGROUND

Women treated with tamoxifen for breast cancer are at increased risk of endometrial cancer. We conducted a retrospective cohort study to evaluate the risk of second primary cancers after adjuvant tamoxifen therapy for breast cancer in Japan.

PATIENTS AND METHODS

The subjects of the study were 6148 women who had been diagnosed with stage I, II, or IIIA unilateral primary breast cancer and had received surgical treatment during the period from January 1982 through December 1990 at nine institutions in Japan. The information on each patient was obtained from medical records or a prospectively compiled computer database at each institution.

RESULTS

Of the 6148 women, 3588 (58.4%) were administered tamoxifen as an adjuvant treatment and 2560 (41.6%) were not administered. Median follow-up periods were 7.64 years for tamoxifen-treated patients and 8.10 years for non-tamoxifen-treated patients, respectively. The duration of tamoxifen treatment was mostly two years or less (80.7%), and few patients received tamoxifen for more than five years. The cumulative incidence rates of all second cancers at 10 years were 4.61% and 4.09% among tamoxifen-treated and non-tamoxifen-treated patients (P = 0.62), respectively, and the incidence rate ratio (IRR) for all second cancers was 1.06 (95% confidence interval (CI): 0.77-1.47) after adjustment of several covariates. The numbers of endometrial cancers was 9 and 3 among tamoxifen-treated and non-tamoxifen-treated patients, respectively, and the IRR was 2.37 (95% CI: 0.64-8.77, P = 0.20). Of the 12 patients who developed endometrial cancer, 4 died of cancer (for 3 of them, the cause of death was breast cancer), and the other 8 patients were alive as of March 1996. Stomach cancer was the most frequent second cancer and the IRR was 1.34 (95% CI: 0.76-2.38, P = 0.31). There was no substantial increase in any other type of gastrointestinal cancer such as colorectal and liver cancers among tamoxifen-treated patients.

CONCLUSIONS

The incidence and risk of second primary cancers associated with tamoxifen therapy is low. The potential benefit of adjuvant tamoxifen therapy in breast cancer patients outweighs the risk of second primary cancers for Japanese breast cancer patients.

Prognostic impact of tissue inhibitor of matrix metalloproteinase-1 in esophageal carcinoma

Tissue inhibitor of metalloproteinase-1 (TIMP-1) inhibits the activity of matrix metalloproteinase, which may play an important role in carcinoma invasion and metastasis. TIMP-1 is thus considered to inhibit carcinoma invasion and metastasis. However, TIMP-1 possesses another important function, cell growth promotion. The clinical significance of TIMP-1 expression has not been fully determined in esophageal carcinoma. We thus examined the expression of TIMP-1 mRNA in tumor (T) and corresponding normal (N) tissues of 85 esophageal carcinoma cases by RT-PCR. The T:N ratio of TIMP-1 mRNA expression in each case was evaluated semi-quantitatively with adjustment by an internal control gene. The mean T:N ratio was 2.0 (range 0.2-6.5). When comparing high-expression cases (T:N > 2.0, n = 37) with low-expression cases (T:N < or = 2.0, n = 48), the former showed a significantly higher frequency of lymph vessel invasion, vascular vessel invasion, lymph node metastasis and advanced-stage disease. The former cases showed a poorer prognosis than the latter. Multivariate analysis disclosed that TIMP-1 expression status was an independent determining factor for prognosis. Our findings suggest that TIMP-1 expression correlates with tumor extension of esophageal carcinoma and might, if validated, prove useful as a novel prognostic marker for esophageal carcinoma.

Expression of tissue inhibitor of matrix metalloproteinase-1 in human breast carcinoma

Tissue inhibitor of metalloproteinase-1 (TIMP-1) is an inhibitor of matrix metalloproteinase (MMP) in human carcinomas. TIMP-1 is thus considered to inhibit carcinoma invasion and metastasis. On the other hand, recent reports have disclosed that TIMP-1 also possesses a growth-promoting function. The clinical significance of TIMP-1 expression has not been fully determined in breast carcinoma. We thus examined the expression of TIMP-1 mRNA in tumor tissues of 100 breast carcinoma cases by a reverse transcriptase-polymerase chain reaction assay. The expression of TIMP-1 mRNA in each case was evaluated semi-quantitatively with adjustment for the TIMP-1 expression in a control breast carcinoma cell line, MCF7. There was a significant inverse correlation between the TIMP-1 expression and lymph node metastasis (p<0.05). A multivariate analysis disclosed that TIMP-1 expression status was an independent determinant factor for lymph node metastasis. In addition, the tumors with positive estrogen or progesterone receptors showed a higher TIMP-1 mRNA expression than those without the receptors, but this did not reach statistical significance. The findings suggest that the breast tumors with high TIMP-1 expression might show less malignant potential than those with low TIMP-1 expression.

RT-PCR detection of breast cancer cells in sentinel lymph modes

Sentinel lymph node (SLN) biopsy is being evaluated in breast cancer patients to improve detection of metastases and to guide therapy with minimal morbidity. The aim of this study was to increase the sensitivity of tumor cell detection in SLNs using superior reverse transcription polymerase chain reaction (RT-PCR) for carcinoembryonic antigen (CEA) and mammaglobin (MMG) analysis rather than current methods which fail to identify clinically relevant disease in many patients. In seventy stage I and II breast cancer patients dye-guided lymph node mapping was performed and the SLNs were divided alternately for RT-PCR or hematoxylin and eosin staining (H&E). RT-PCR and H&E diagnosis of SLNs were compared. SLNs were identified in 66/70 (94.3%) patients. Seventeen patients (26. 2%) had histological metastasis in SLNs. CEA was expressed in 25.0% of 48 patients with H&E negative SLNs, and MMG was expressed in 20. 8%. SLNs could predict axillary lymph node status with 95.4% accuracy and 6.3% false negative rate by H&E. Moreover, RT-PCR improved these to 98.5% and 2.8%, respectively. SLN diagnosis using RT-PCR is a powerful and sensitive method, which increases the accuracy of clinical staging and may provide more informed choices for appropriate therapeutic management of breast cancer patients.

L-myc restriction fragment length polymorphism in Japanese patients with esophageal cancer

L-myc polymorphism is a representative genetic trait related to an individual's susceptibility to several cancers. However, there have been no reports concerning the association between esophageal cancer and L-myc polymorphism. To analyze the distribution of polymorphism in Japanese patients with esophageal cancer, a molecular genotyping method using a polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) was used. Based on an analysis of 65 Japanese patients with esophageal cancer and 107 healthy control subjects, a significant difference was observed in either the distribution of genotypes (P=0.012) or of allele frequencies between the two groups (P=0.004). The relative risk of esophageal cancer for genotypes including the shorter allele was 2.9 compared to the longer allele homozygote. Furthermore, the patients with S-allele had a tendency for poor prognosis among those with three genotypes. A significant difference between the distribution of genotypes and the incidence of lymph node metastasis was found based on the clinicopathological features of the cancers. These results suggest that L-myc polymorphism may be implicated as a genetic trait affecting an individual's susceptibility to esophageal cancer, at least among Japanese patients.

Generation of specific antitumor reactivity by the stimulation of spleen cells from gastric cancer patients with MAGE-3 synthetic peptide

The induction of cytotoxic T lymphocytes (CTL) from peripheral blood mononuclear cells (PBMC) using MAGE peptide has been investigated in order to use MAGE antigens immunotherapeutically. We therefore developed a simplified method for inducing peptide-specific CTL that kill tumor cells expressing MAGE from the PBMC of either healthy donors or even cancer patients. Since the spleen is a major lymphoid organ, we used a simple method to examine the capacity of spleen cells to generate MAGE-specific CTL by in vitro stimulation with MAGE peptide in gastric cancer patients. The CTL responses could thus be induced from unseparated spleen cells in HLA-A2 patients with gastric carcinoma expressing MAGE-3 by stimulating these cells with autologous spleen cells pulsed with HLA-A2-restricted MAGE-3 peptide as antigen-presenting cells and by using keyhole limpet hemocyanin and interleukin-7 for the primary culture. The induced CTL were thus able to lyse HLA-A2-positive carcinoma cells transfected with MAGE-3 and expressing MAGE-3, as well as the target cells pulsed with the peptide, in an HLA-class-I or -A2-restricted manner. Since MAGE-specific CTL could be induced from the spleen cells of gastric cancer patients, the spleen appears to play an important role in either clinical tumor vaccination or the treatment of cancer patients by adoptive immunotherapeutic approaches using the MAGE peptide.

An effective pre-operative chemoimmunotherapy regimen against advanced gallbladder carcinoma: a case report

We designed a chemoimmunotherapy regimen with a single dose of mitomycin C (MMC) followed by subsequent OK-432 injections, since the ability of peripheral blood mononuclear cells (PBM) to generate OK-432 activated killer cells had previously been shown to be augmented by MMC in cancer patients. We herein report on a case with far advanced gallbladder carcinoma who demonstrated a remarkable response to this chemoimmunotherapy, and thus underwent a curative resection. A 67 year-old Japanese woman was diagnosed as having gallbladder carcinoma with invasion to the liver and portal vein, as well as obvious lymph node metastasis. Since these findings suggested the tumor to be unresectable at that time, our chemoimmunotherapy regimen with MMC and OK-432 was administered. After four courses of therapy, a computed tomography (CT) scan revealed the disappearance of both tumor invasion to the surrounding organs and lymph node metastasis, which therefore prompted us to attempt a radical tumor resection. The histology of the resected specimen revealed that the majority of cancer cells had been killed by the pre-operative therapy and that only remnants of viable cancer cells were found in a part of the neck of the gallbladder and in 2 regional lymph nodes. This experience thus suggests the effectiveness of our chemoimmunotherapy regimen against gallbladder carcinoma.

Expression of pyrimidine nucleoside phosphorylase mRNA plays an important role in the prognosis of patients with oesophageal cancer

To clarify the significance of the expression of pyrimidine nucleoside phosphorylase (PyNPase) mRNA as a predictive factor for the prognosis of patients with oesophageal carcinoma, the PyNPase mRNA in the tumours and normal tissues from 55 resected cases of oesophageal carcinoma was examined by a reverse transcription polymerase chain reaction (RT-PCR). As a result, a positive correlation was observed between the tumour/normal (T/N) ratio of the expression of PyNPase mRNA by RT-PCR and that of the enzyme activity of PyNPase based on the findings of an enzyme linked immunosolvent assay (r = 0.594, P = 0.009). The T/N ratio of the expression of PyNPase mRNA was significantly higher in the cases with lymph vessel invasion (P = 0.013), lymph node metastasis (P = 0.0016), and an advanced stage of the disease (P = 0.021) than those without these factors. The patients with a higher T/N ratio of PyNPase mRNA showed significantly worse prognosis than those with a lower T/N ratio (P = 0.023 with log-rank tests). A multivariate analysis for the cumulative survival rates revealed that a high T/N ratio of the expression of PyNPase mRNA was independently related to a poor prognosis. These findings suggested that the determination of PyNPase mRNA by RT-PCR thus appears to be a new useful parameter for identifying both a poor prognosis and a highly malignant potential of oesophageal carcinoma.

Lack of DMBT1 expression in oesophageal, gastric and colon cancers

Loss of sequences from human chromosome 10q has been reported in several different cancers. Recently, a second candidate tumour-suppressor gene, DMBT1, was identified in this chromosomal region. We studied the mRNA expression and homozygous deletion of this gene in human oesophageal, gastric and colon cancers. Reverse transcriptase polymerase chain reaction (RT-PCR) amplification demonstrated that 23 (53.5%) of 43 oesophageal, 5 (12.5%) of 40 gastric, and 4 (16.7%) of 24 colorectal cancer cases showed an apparent reduction in DMBT1 mRNA in tumour tissues compared with paired normal tissues. Twelve out of 15 oesophageal cancer cell lines also showed no expression. We next studied homozygous deletions within the DMBT1 gene in oesophageal cancers by using duplex PCR. Consequently, it was recognized in five (11.6%) of the primary tumours and two (13.3%) of the cell lines. These findings suggest that DMBT1 may act as a tumour-suppressor gene not only in brain tumours but also in gastrointestinal cancers, especially in oesophageal cancers.

Up-regulated pyrimidine nucleoside phosphorylase in breast carcinoma correlates with lymph node metastasis

BACKGROUND

The clinical significance of pyrimidine nucleoside phosphorylase (PyNPase) activity in breast carcinomas has never been determined.

MATERIALS AND METHODS

In 41 cases of breast carcinoma, the enzyme activity of PyNPase was determined by the high performance liquid chromatography (HPLC) assay and its value was analyzed with clinicopathologic variables. The expression level of mRNA was examined by the semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) assay and compared with the enzyme activity.

RESULTS

The higher activity of PyNPase was significantly correlated not only with the presence of vascular permeation (P = 0.02) but of lymph node metastasis (P = 0.02). The mRNA expression correlated well with the enzyme activity (r = 0.74, P < 0.01). A multivariate analysis disclosed the PyNPase factor to be associated with lymph node metastasis. In addition, 17 (41%) showed positive staining only in the tumor stromal cells and 18 (44%) cases showed positive staining in both the tumor stromal cells and the carcinoma cells by immunohistochemical study.

CONCLUSIONS

These findings suggest that PyNPase activity is a new marker predicting the malignant potential of breast carcinomas, especially with respect to lymph node metastasis, and that the RT-PCR assay is a more useful method than direct evaluation of PyNPase activity.

Expression of insulin-like growth factor 2 mRNA in human gastric cancer

Insulin-like growth factor 2 (IGF2) stimulates cell proliferation and development in normal human growth. In several human cancers, the IGF2 gene is overexpressed and is thus considered to be a growth factor for tumors mediated through both the paracrine and autocrine pathways. However, the significance of IGF2 mRNA expression in gastric cancer has yet to be clarified. We semi-quantitatively measured the expression of IGF2 mRNA in 57 Japanese cases of gastric cancer by means of the reverse transcription polymerase chain reaction and also analyzed the relation between the IGF2 expression status and other clinicopathologic factors. We also performed immunohistochemical staining for IGF2. In 41 of 57 cases (72%), the expression of IGF2 mRNA was greater in tumor tissue (T) than in normal tissue (N). The average tumor/normal (T/N) expression ratio of IGF2 mRNA corrected for that of control gene mRNA was 1.42, while ranging from 0.36 to 3.65. The T/N ratio of infiltrative-type cancers was greater than that of expanding-type cancers (p<0.05). The cases with lymphatic permeation showed a greater T/N ratio than those without lymphatic permeation in expanding-type cancers (p<0. 05). Immunohistochemical staining revealed IGF2 to be detected in cancer cells themselves, especially at the margin of the cancer tissue. The IGF2 gene may thus play an important role in lymph vessel permeation especially in expanding-type gastric cancers.

Expression spectrum of melanoma antigen-encoding gene family members in colorectal carcinoma

OBJECTIVE

The 12 members of the human melanoma antigen-encoding (MAGE) gene family encode tumor-specific peptide antigens. Some antigens coded by the MAGE genes are potentially useful for cancer-specific immunotherapy. However, little information on the expression of these genes in human colon carcinomas is available. We investigated the expression of 10 of the 12 genes in human colon tissue.

DESIGN

Eighty pairs of tumor and normal tissue samples from the human colon were studied by means of reverse transcription-polymerase chain reaction.

RESULTS

None of the genes was expressed in the 80 control samples of normal tissue. On the other hand, expression was recognized in tumor samples, ranging from 5% of samples for MAGE-6 to 44% for MAGE-8. Seventy of the 80 tumor samples (88%) expressed at least 1 of the 10 MAGE genes. The frequency of liver metastasis was significantly higher in cases with tumor samples that expressed MAGE-3 than in those that did not express this gene. This tendency was not observed for other members of the MAGE gene family. No significant differences were observed in the other clinicopathologic factors between any MAGE-positive and -negative tumor cases.

CONCLUSIONS

The MAGE genes were exclusively expressed in carcinoma tissues and not in normal tissues of the colon. The finding that nearly 90% of tumors expressed at least one MAGE gene indicates the possible clinical use of this gene for both immunotherapy and molecular diagnosis.

Motility related protein 1 (MRP1/CD9) expression in colon cancer

It is important to detect genes that may be good prognostic markers for colon cancer patients. With this in mind, we identified the motility related protein-1 (MRP1/CD9) gene in human colon tissues. The aim of this study was to clarify the significance of MRP1/CD9 gene expression in human colon cancers. We performed the differential mRNA display technique between tumor/normal paired samples of the colon and identified MRP1/CD9. Eighty-two surgical specimens of primary colorectal cancer were analyzed by means of reverse transcription-PCR for the MRP1/CD9 gene. Its expression status and clinicopathological variables were analyzed univariately and multivariately. The MRP1/ CD9 mRNA expression was positive in 56 cases and negative in 26 cases. The MRP1/CD9 negative cases showed a significantly higher frequency of venous-vessel invasion and liver metastasis, or a worse prognosis than the MRP1/CD9 positive cases (P < 0.05). Multivariate analysis with the Cox regression model disclosed that MRP1/CD9 expression was an independent prognostic factor distinct from the lymph node status. The findings imply that the study of MRP1/CD9 expression may be useful for predicting prognosis of patients with colorectal cancer.

Association between restriction fragment length polymorphism of the L-myc gene and susceptibility to gastric cancer

BACKGROUND

L-myc polymorphism has been documented to be a representative genetic trait which is related an individual's susceptibility to several cancers. However, there have been no reports concerning any significant association between susceptibility to gastric cancer and L-myc polymorphism.

METHODS

The distribution of L-myc polymorphism in 61 patients with gastric cancer was determined by polymerase chain reaction-based restriction fragment length polymorphism and compared with that of 107 healthy control subjects.

RESULTS

There was a significant difference in the distribution of both genotypes (P = 0.024) and allele frequencies (P = 0.026) between the two groups. The relative risk of gastric cancer for genotypes with the shorter (S) allele was 3.09 compared with the longer (L) allele homozygote. No significant correlation with clinicopathological features of the cancers except for prognosis was found. The patients with SS genotypes had a worse prognosis than those with LL or LS genotypes (P = 0.029).

CONCLUSION

L-myc polymorphism may be significant in an individual's susceptibility to gastric cancer in Japan, and may be a useful marker for identifying patients at high risk of developing gastric cancer.

Expression of ornithine decarboxylase mRNA and c-myc mRNA in breast tumours

We examined the expression of ornithine decarboxylase (ODC) mRNA in 53 female cases of breast cancer by a reverse transcriptase-polymerase chain reaction (RT-PCR) assay to determine the clinicopathologic significance of its expression. A significantly higher expression of ODC mRNA was, observed in younger patients than in older patients. The patients with a larger sized tumour possessed a significantly higher expression of ODC mRNA. In addition, the cases with a poor prognosis showed significantly higher expression of ODC. Previous studies have reported in vivo and in vitro correlation between the expression of ODC and c-myc genes in human carcinomas. We disclosed a significant correlation between these genes in primary breast carcinomas. We conclude that the expression of ODC may potentially be a new biological marker for breast carcinoma.

Clinical significance of molecular detection of carcinoma cells in lymph nodes and peripheral blood by reverse transcription-polymerase chain reaction in patients with gastrointestinal or breast carcinomas

PURPOSE

This study evaluates the clinical significance of detection of carcinoembryonic antigen (CEA) mRNA in the dissected lymph nodes and peripheral blood samples of patients with gastrointestinal or breast carcinomas.

PATIENTS AND METHODS

A total of 406 lymph nodes obtained from 65 patients were analyzed by both histologic and molecular examination of CEA-specific reverse transcriptase-polymerase chain reaction (RT-PCR). Peripheral blood samples from another 102 patients were also analyzed by CEA-specific RT-PCR. Patients were followed up prospectively for 24 +/- 12 months.

RESULTS

Of 406 lymph nodes, the positive detection rate increased from 20% by histologic examination to 60% by RT-PCR examination. The recurrence rate was 40% in 15 cases showing positive results in both examinations, 14% in 29 cases showing histologically negative but RT-PCR positive results, and none in 21 cases showing negative results in both examinations. The positive detection rate for CEA mRNA in peripheral blood samples increased with advancing stage of disease. With respect to 62 curatively operated cases, CEA mRNA was detected in 12 cases. Four of these 12 cases developed metastatic disease after surgery whereas none of 50 cases negative by RT-PCR developed metastasis.

CONCLUSION

It has been shown that RT-PCR is a powerful tool to detect CEA mRNA in the lymph nodes or the peripheral blood. This is potentially very useful to determine high-risk patients for metastasis. Serial analysis is warranted to assess the long-term significance of this method and its therapeutic and prognostic implications.

Neoadjuvant chemoimmunotherapy with cisplatin and low-dose interleukin-2 for locally advanced esophageal carcinoma

After a single dose of cisplatin, the ability of peripheral blood mononuclear cells (PBMC) to generate lymphokine-activated killer (LAK) cells was significantly augmented in cancer patients. Based on this clinical finding, the patients with locally advanced esophageal carcinoma were thus treated with a combination of cisplatin and low-dose interleukin-2 (IL-2) in a neoadjuvant setting. Four patients with squamous cell carcinoma of the esophagus (T3 or T4 disease) were preoperatively treated with a regimen consisting of 50 mg/m2 cisplatin on day 1, followed by IL-2 from day 4 through day 8, when the ability of PBMC to generate LAK cells had been shown to be significantly augmented. After two to four courses of the preoperative therapy, one patient achieved a histologic CR, one showed PR and one MR. No severe toxicity was encountered. All patients thereafter underwent surgery. The median survival of these patients was 47.5 months and three of the patients had been disease free for 43 to 62 months after the initiation of the therapy. The combination of cisplatin and low-dose IL-2 administered in a neoadjuvant setting seems to result in an improved survival of locally advanced squamous cell carcinoma of the esophagus.

Clinical significance of integrin alpha 6 mRNA expression in gastric carcinoma

Integrin alpha 6 is believed to be involved in malignant biological development. High tumor/normal (T/N) ratio of integrin alpha 6 was observed in intestinal type tumors in gastric carcinoma. In an immunohistochemical study, an intense and continuous staining was seen at the basement layer in the intestinal type tumors. Concerning the variant, there was a significant correlation between the expression ratio of variant B/variant A and the depth of tumor invasion. In conclusion, i) integrin alpha 6 expression was intimately correlated with histologic differentiation, and ii) the overexpression of variant B may be correlated with tumor invasion of gastric carcinoma.

Analysis of ornithine decarboxylase messenger ribonucleic acid expression in colorectal carcinoma

PURPOSE

Ornithine decarboxylase (ODC) is a rate-limiting enzyme for polyamine synthesis. An elevated protein level of ODC was observed in the tumors. There has been, however, little information reported so far on the expression of ODC messenger ribonucleic acid (mRNA) in clinical colorectal carcinomas. In vitro studies disclosed that the transcriptions of the ODC gene is regulated by the c-myc gene.

METHODS

The expression of ODC and c-myc mRNA in biopsy specimens obtained from both tumor tissue and the corresponding normal tissue was examined by the reverse transcriptase polymerase chain reaction method in 40 cases of colorectal carcinoma.

RESULTS

The expression of ODC mRNA was observed in both tumor tissue and normal tissue. The tumor to normal ratio of ODC mRNA was higher in cases with deeply invasive tumors than in cases with shallow tumors, and it was also higher in Dukes B or C cases than in Dukes A cases. There was a significant correlation between the tumor to normal ratio of c-myc mRNA and that of ODC mRNA in each case.

CONCLUSIONS

These findings suggested that 1) the study of the expression of ODC mRNA may be useful for preoperatively predicting more advanced disease of colon carcinoma, and 2) there was a significant correlation between expression of ODC and c-myc mRNA in the clinical samples, which was similar to the findings of a previous in vitro study.

Expression of the MAGE gene family in human gastric carcinoma

MAGE genes code tumor antigens that are recognized by cytolytic T lymphocytes and have been shown to be expressed in various malignant tumors. However, there is still little information on the expression of the MAGE gene family except for reports of MAGE-1 and -3. In this study, we therefore investigated the expression of MAGE-4, -6, -8, -9, -10, -11 and -12, as well as MAGE-1, -2 and -3 in both cell lines and surgical samples of gastric carcinoma, using reverse transcriptionPCR. Of the investigated 11 cell lines, MAGE-4, -6, -8, -9, -10, -11 and -12 were detected in 8 (73%), 6 (55%), 2 (18%), 59 (44%), 6 (55%), 4 (36%), and 7 (64%), respectively. No expression of these genes was seen in any of the 54 samples of normal gastric tissue. In contrast, the tumor tissue samples were found to express MAGE-4, -6, -8, -9, -10, -11, and -12 in 18 (33%), 13 (24%), 6 (11%), 10 (19%), 5 (9%), 13 (24%), and 10 (19%), respectively. Forty-four (82%) of 54 gastric tumors expressed at least one of these genes. No significant correlation was observed between the expression of MAGE genes and any specific clinicopathological factors. These results may hopefully prove to be useful in developing strategies for tumor-specific immunotherapy of gastric carcinoma using MAGE gene products.