Search

Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) has recently been identified as one of the vascular endothelial growth factors, and it is considered that the overexpression of EG-VEGF in colon cancer is related to hepatic metastasis. In this study, we report our recent novel findings of the involvement of EG-VEGF in cell invasion of colon cancer cells. Colon cancer cell lines (DLD-1 and HCT116) with high expression of prokineticin receptor (PK-R) 1 and 2 were stimulated with the EG-VEGF protein. Furthermore, Matrigel cell invasion assay was performed to examine the changes in cancer cell invasion. In addition, we investigated the mRNA expression of matrix metalloproteinase (MMP)-2, -7 and -9 in cancer cells. Finally, the EG-VEGF receptor on the colon cancer cell membrane was blocked by anti-PK-R1 and -PK-R2 antibodies to study whether cell invasion ability would be altered. In colon cancer cell lines where the expression of PK-R1 and 2 was confirmed, stimulation with EG-VEGF increased cell invasion a maximum of ~3-5 times. Furthermore, an increase in the mRNA and protein expression of MMP-2, -7 and -9 was observed. We also observed that the cell invasion rate decreased only after exposure to the anti-PK-R2 antibody. The study showed that the EG-VEGF protein may act on MMP-2, -7 and -9 via PK-R2 to strengthen cell invasion ability in colon cancer cell lines.

We examined serum SLX for its significance as a tumor marker in 109 colorectal cancer patients. There a close correlation with immunohistochemical expression of SLX and serum SLX level. Serum SLX was positive in 16.5% of 109 patients with colorectal cancers. There was no significant correlation between serum SLX level and histologic type or primary tumor status. There were significant correlations between serum SLX positive rates and both lymph node and hematogenous metastasis. In 7 SLX positive cases who underwent curative resection, 4 patients had already recurrence in the liver. Our findings suggest that serum SLX values may be a biologic marker of metastasis.

The RIN1 gene, located on chromosome 11q13.2, is a molecule consisting of a coding region of 2352 bp, has a domain on the 3' side that binds to H-Ras protein, and is presumed to be an important molecule in an intracellular signaling pathway. Since the RIN1 molecule belonging to the effector molecules of H-Ras has not been reported in colorectal or other digestive tract cancers to date, we investigated how the RIN1 gene was involved in colorectal cancer. Fifty-two (51.5%) of 101 colorectal cancer specimens strongly expressed the RIN1 gene compared to the adjacent normal colorectal tissue. The 5-year survival rate of patients positive for the expression of the RIN1 gene was significantly poorer at 55% than that (83%) of patients negative for the expression of the RIN1 gene. Also, we confirmed that RIN1 protein was localized chiefly in the cytoplasm of colorectal cancer cell lines, and bound to 14-3-3 protein, but not to Ras protein. These results indicate that the RIN1 gene serves as an important signal transduction system for evaluating the malignancy of colorectal cancer.

The PPP1R3 gene is located on chromosome 7q31, and encodes protein phosphatase 1 (regulatory 3). It has been reported that the inactivation of various phosphatase proteins causes abnormalities in cell division and cell growth systems. We analyzed alterations in the PPP1R3 gene and its relationship to tumor progression and metastasis. Deletion mutants of exons containing mutations were prepared and assayed for intranuclear transcription activity. SSCP analysis of PPP1R3 showed abnormal patterns in 6 (12%) of the 50 colorectal cancers. DNA sequencing of the 6 samples showing abnormal SSCP patterns confirmed point mutations in exon 4 in 4 samples, and in exon 1 in 2 samples. PPP1R3 gene alterations correlated with lymph node and liver metastases. Enhancement of luciferase activity by the full PPP1R3 gene was confirmed. However, when point mutation-containing exon 1 or 4 deletion mutants were examined for luciferase activity, enhancement of activity was decreased in the exon 1 deletion mutants, while no enhancement of the activity was noted in the exon 4 deletion mutants. These findings suggest that protein phosphatase 1 (regulatory 3) protein is involved in intracellular processes in some colorectal cancers and may play a role in metastasis.

This trial was performed to determine the efficacy and progression-free and overall survivals of patients with advanced ovarian cancer who had been treated with intraperitoneal hyperthermic chemotherapy (IPHC). Ten patients with advanced ovarian cancer participated in this trial and were treated with IPHC. The median progression-free and overall survival rates for all patients treated in this study were 41.2 and 70.2 months, respectively. Two of ten patients received optimal primary cytoreduction surgery followed by IPHC; four of ten, optimal interval debulking surgery followed by IPHC; and four of ten, negative second-look operation followed by IPHC. The groups had 5 and 14.5, 17.75 and 38, and 82.75 and 130.25 months median progression-free and overall survival rates, respectively. Grades 3-4 toxicity included myelosuppresion, and nephropathy was detected. One patient required blood transfusions due to grade 4 anemia and thrombocytopenia. Another patient developed grade 3 nephrotoxicity but did not require continuous hemo-dialysis. IPHC was feasible, produced manageable toxicity, and showed promise for the treatment of advanced ovarian cancer. Negative second-look laparotomy followed by IPHC was especially effective when consolidation intraperitoneal chemotherapy had been indicated. It produced excellent median progression-free and overall survival rates.

The chromosome region 11q is frequently deleted in colorectal cancers. The PPP2R1B tumor suppressor gene, encoding the beta isoform of the A subunit of serine/threonine-specific protein phosphatase 2A (PP2A-Abeta), located at 11q22-23, is inactivated in patients with cancer. The present study investigated whether or not PP2A-Abeta is altered in colorectal cancers. We searched for alterations of the PPP2R1B gene and interactions between PP2A-Abeta and PP2A-C proteins in 50 surgically resected colorectal cancer tissues. Missense mutations and homozygous deletions of the PPP2R1B gene were found in 4 of 50 patients (8%) and in 1 of 50 patients, respectively, with colorectal cancers. Deletions and/or point mutations within 412-601 amino acid sequences (binding regions of PP2A-C protein) of the PPP2R1B gene derived from colorectal cancer tissues inhibited co-immunoprecipitation of PP2A-Abeta and PP2A-C proteins. These finding suggested that the PPP2R1B gene functions as a tumor suppressor gene and acts as a molecular switch that becomes active in response to specific up-stream signals. Upon activation, the gene alters the activities of specific downstream target proteins for the cell cycle regulations and/or metabolism in some colorectal cancers.

The chromosome region 11q is frequently deleted in colorectal cancers. The PPP2R1B tumor suppressor gene, encoding the beta isoform of the A subunit of serine/threonine-specific protein phosphatase 2A (PP2A-Abeta), located at 11q22-23, is inactivated in patients with cancer. The present study investigated whether or not PP2A-Abeta is altered in colorectal cancers. We searched for alterations of the PPP2R1B gene and interactions between PP2A-Abeta and PP2A-C proteins in 50 surgically resected colorectal cancer tissues. Missense mutations and homozygous deletions of the PPP2R1B gene were found in 4 of 50 patients (8%) and in 1 of 50 patients, respectively, with colorectal cancers. Deletions and/or point mutations within 412-601 amino acid sequences (binding regions of PP2A-C protein) of the PPP2R1B gene derived from colorectal cancer tissues inhibited co-immunoprecipitation of PP2A-Abeta and PP2A-C proteins. These finding suggested that the PPP2R1B gene functions as a tumor suppressor gene and acts as a molecular switch that becomes active in response to specific up-stream signals. Upon activation, the gene alters the activities of specific downstream target proteins for the cell cycle regulations and/or metabolism in some colorectal cancers.

The chromosome region 17p shows frequently allele losses/mutations in colorectal cancers, and such frequent genetic alterations are a hallmark of the presence of tumor-suppressor gene. The RPH3AL, which is located at 17p13, has been identified from a candidate 17p13 medulloblastoma tumor suppressor locus. The aim of this study was to determine whether it is also altered in colorectal cancers. Mutational analyses of the RPH3AL gene were performed on DNA samples from 50 primary colorectal cancer specimens using polymerase chain reaction-single strand conformation polymorphism, and DNA sequencing. Six missense mutations producing amino acid substitution in coding region of the RPH3AL gene were detected in 50 primary colorectal cancer patients. The RPH3AL gene may play a role as a tumor-suppressor gene in fraction of colorectal cancers, but a minority show RPH3AL gene mutations. Somatic RPH3AL mutations were identified, providing support for an authentic role as tumor-suppressor gene in colorectal cancer, but only in a minority of cases.

We studied the Cd44v8-10 expression in gallbladder cancer immunohistochemically. Eighteen of 37 gallbladder cancer tissues expressed CD44v8-10. There were significant correlations between CD44v8-10 immunoreactivity and perineural invasion, venous invasion, and lymph node metastasis. Patients with CD44v8-10-positive tumors showed poor prognoses, whereas those with CD44v8-10-negative tumors had favorable prognoses. A multivariate analysis using the Cox regression model showed the immunoreactivity of CD44v8-10 to be an independent prognostic indicator of gallbladder cancer. The results suggest that CD44v8-10 expression may be a biologic marker of prognostic significance in gallbladder cancer.