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Colorectal cancer (CRC) is a leading cause of cancer-related death worldwide. The spheroid colony formation assay is a useful method to identify cancer stem cells (CSCs). Using the DLD-1 and WiDr CRC cell lines, we performed microarray analyses of spheroid body-forming and parental cells and demonstrated that aldolase, fructose-bisphosphate C (ALDOC) was overexpressed in the spheroid body-forming cells of both lines. Cells transfected with small interfering RNA against ALDOC demonstrated lower proliferation, migration, and invasion compared with negative control cells. Both the number and size of spheres produced by the CRC cells were significantly reduced by ALDOC knockdown. Additionally, inhibition of ALDOC reduced lactate production. Immunohistochemistry was used to analyze ALDOC protein expression in tissues from 135 CRC patients and revealed that 66 (49%) cases were positive for ALDOC. The ALDOC-positive cases were associated with higher T and M grades and, as determined by Kaplan-Meier analysis, a poorer prognosis. Univariate and multivariate analyses indicated that ALDOC expression was an independent prognostic factor for CRC patients. Furthermore, ALDOC expression was associated with CD44 expression. These results suggest that ALDOC contributes to CRC progression and plays an important role in CSCs derived from CRC., (© 2022 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.)

Background: Genes encoding transmembrane proteins expressed specifically in cancer cells may be ideal therapeutic targets or biomarkers for diagnosis., Methods: In the present study, we investigated the expression and function of PCDHB9, which encodes transmembrane protein protocadherin B9 in colorectal cancer (CRC)., Results: Immunohistochemical analysis showed that 39 (26%) of 148 CRC cases were positive for protocadherin B9. Expression of protocadherin B9 correlated with lymphatic invasion, venous invasion, and T classification and was weakly detected in adenomas by immunohistochemistry. Although PCDHB9 knockdown did not change cell growth and invasion activity in CRC cell lines, cell adhesion to fibronectin was significantly reduced by PCDHB9 knockdown. Expressions of ITGA3, ITGA4, ITGA5, ITGB1, and ITGB6 were significantly reduced by PCDHB9 knockdown. In addition, the number of spheres was significantly decreased by PCDHB9 knockdown., Conclusion: These results suggest that protocadherin B9 might be associated with colorectal tumorigenesis and cancer progression in CRC., (© 2022 S. Karger AG, Basel.)

Colorectal cancer (CRC) is the second leading cause of cancer-related mortality worldwide. Kinesin Family Member C1 (KIFC1) has been proposed as a promising therapeutic target due to its pivotal role in centrosome clustering to mediate cancer cell progression. This study aimed to analyze the expression and biological function of KIFC1 in CRC. Immunohistochemically, 67 (52%) of 129 CRC cases were positive for KIFC1 and statistically associated with poorer overall survival. KIFC1 small interfering RNA (siRNA)-transfected cells demonstrated lower cell proliferation as compared to the negative control cells. A specific KIFC1 inhibitor, kolavenic acid analog (KAA) drastically inhibited CRC cell proliferation. Microarray analysis revealed that KAA-treated CRC cells presented reduced ZW10 interacting kinetochore protein (ZWINT) expression as compared to control cells. Immunohistochemical analysis demonstrated that 61 (47%) of 129 CRC cases were positive for ZWINT and ZWINT expression was significantly correlated with KIFC1 expression. ZWINT-positive cases exhibited significantly worse overall survival. KIFC1 siRNA-transfected cells showed reduced ZWINT expression while ZWINT siRNA-transfected cells decreased cell proliferation. Both KIFC1 and ZWINT knockdown cells attenuated spheroid formation ability. This study provides new insights into KIFC1 regulating ZWINT in CRC progression and its potential as a therapeutic target., (© 2021 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.)

Intelectin-1 (ITLN1) is an adipokine with an anti-inflammatory function that is involved in neoplastic diseases such as pleural mesothelioma and gastric and prostate cancers. However, the expression and function of ITLN1 in colorectal cancer (CRC) remain unknown. To identify novel prognostic markers or therapeutic targets for CRC, we focused on ITLN1 protein. By immunohistochemistry, 87 (59%) of 148 CRC cases showed reduced expression of ITLN1. ITLN1-reduced CRC cases were associated with higher M grades (P = 0.0017) than ITLN1-retained CRC cases. Furthermore, the cases with ITLN1 retained expression tended toward a more favorable prognosis than those with reduced expression. Cell growth of the CRC cell lines transfected with ITLN1 siRNA were greater than those of the negative control cell lines transfected with siRNA. Levels of phosphorylated epidermal growth factor receptor, Erk and Akt were higher in the CRC cells transfected with ITLN1 siRNA than in control cells. Immunohistochemical analysis of human colorectal polyp specimens also revealed a sequential decrease in the expression of ITLN1 through both the conventional adenoma-carcinoma pathway and the serrated pathway. These results indicated that ITLN1 might play an important role in regulating colorectal tumorigenesis., (© 2020 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.)

BRAF V600E mutation accounts for up to 90% of all BRAF mutations in human colorectal cancer (CRC), and constitutively activates the MEK-MAPK pathway. It is recognized that neutralizing mAbs for epidermal growth factor receptor alone are not effective for CRC with BRAF V600E mutation. Therefore, there is increasing interest in identification of the possible therapeutic targets in downstream of BRAF mutation in CRCs. To address this, we studied genome engineered mouse models for colonic neoplasia that has Braf V600E mutation on the basis of Apc inactivation, induced in 2 distinct Cre mouse models, CDX2P-G22Cre and CDX2P-CreER T2 mice. We carried out oligonucleotide microarray analysis for colonic neoplasia generated in these mouse models, and compared gene expression profiles among Kras/Braf WT, Kras-mutated, and Braf-mutated mouse colon tumors to seek new molecular targets corresponding to the KRAS-BRAF-MAPK axis. We found that the expression of the growth regulation by estrogen in breast cancer protein 1 (Greb1) was the most upregulated gene in Braf-mutated mouse tumors compared to Kras/Braf WT counterparts. The silencing of GREB1 significantly reduced the proliferation and tumorigenesis of CRC cell lines, whereas the overexpression of GREB1 promoted cell proliferation. Although GREB1 was first identified as a hormone-responsive gene mediating estrogen-stimulated cell proliferation in endometriosis, breast, and ovarian cancers, these results suggest that RAS-RAF-MAPK signaling upregulates GREB1 expression in CRC, resulting in cellular proliferation. Thus, GREB1 is a possible therapeutic target for CRCs with Braf V600E mutation., (© 2020 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Background/aim: Colorectal adenoma is well known as a precursor lesion of colorectal adenocarcinoma (ADC). We recently reported the significance of CD204 (+) tumor-associated macrophages (TAMs), a vital component of the tumor microenvironment, in the carcinoma development of gastric adenoma. The aim of the present study was to clarify the roles of TAM in the malignant transformation of colorectal adenoma., Materials and Methods: We immunohistochemically assessed the TAM number in 88 tubular or tubulovillous adenomas that were classified into L (low-grade adenomas) or H (high-grade adenomas)., Results: Larger adenoma size, higher frequency of villous structure, loss of proliferation polarity, p53 expression, larger TAM numbers and larger microvessel density (MVD) were detected in Group H than in Group L adenomas. Positive relations were observed between TAM and MVD, proliferation polarity and the expression of p53., Conclusion: CD204 (+) TAM is a novel component in the malignant transformation of colorectal adenoma., (Copyright© 2019, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: Gastrointestinal (GI) cancer, including gastric cancer (GC), colorectal cancer (CRC), and esophageal squamous cell carcinoma (ESCC), is the most common malignancy worldwide. To identify genes that encode transmembrane proteins present in GI cancer, Escherichia coli ampicillin secretion trap libraries were generated from MKN-74 GC cells, and BST2 was identified as overexpressed in GC. This study analyzed the expression and function of the BST2 gene in human GI cancers and examined the relationship between bone marrow stromal antigen-2 (BST-2) expression and GI patient clinicopathologic characteristics., Methods: Expression and distribution of BST-2 protein was analyzed by immunohistochemistry in 180 GC cases, 140 CRC cases, and 132 ESCC cases. Cell growth was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay., Results: Immunohistochemical analysis of BST-2 in GC tissues showed that 65 (36 %) of 180 GC cases were positive for BST-2. Uni- and multivariate analyses demonstrated that BST-2 expression is an independent prognostic classifier of GC patients. Immunohistochemical analysis showed that 46 % of 140 CRC cases and 27 % of 132 ESCC cases were positive for BST-2. In ESCC, BST-2 expression was an independent prognostic predictor for survival. The growth of BST2 small interfering RNA (siRNA)-transfected GC cells was significantly slower than the growth of negative control siRNA-transfected GC cells. The levels of phosphorylated epidermal growth factor receptor, extracellular signal-regulated kinase, and Akt were lower in BST2 siRNA-transfected GC cells than in control cells., Conclusions: The results suggest that BST-2 is involved in tumor progression and serves as an independent prognostic classifier for patients with GC. Because BST-2 is expressed on the cell membrane, BST-2 could be a therapeutic target for GC, CRC, and ESCC.

Background: Oesophageal squamous cell carcinoma (ESCC) and colorectal cancer (CRC) are common types of human cancer. Spheroid colony formation is used to characterize cancer stem cell (CSCs). In the present study, we analyzed the significance of kinesin family 11 (KIF11 in human ESCC and CRC., Materials and Methods: Expression of KIF11 in 105 ESCC and 100 CRC cases was determined using immunohistochemistry. RNA interference was used to inhibit KIF11 expression in ESCC and CRC cell lines., Results: In total, 61 out of 105 (58%) ESCC and 62 out of 100 (62%) CRC cases were positive for KIF11. Expression of KIF11 was not associated with any clinicopathological characteristics. Both the number and size of spheres produced by from TE-5 ESCC cells and DLD-1 CRC cells were significantly reduced upon KIF11 siRNA transfection compared to negative control siRNA transfection., Conclusion: These results indicate that KIF11 plays an important role in CSCs of ESCC and CRC., (Copyright© 2017 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

Mutations in TGFBR2, a component of the transforming growth factor (TGF)-β signaling pathway, occur in high-frequency microsatellite instability (MSI-H) colorectal cancer (CRC). In mouse models, Tgfbr2 inactivation in the intestinal epithelium accelerates the development of malignant intestinal tumors in combination with disruption of the Wnt-β-catenin pathway. However, no studies have further identified the genes influenced by TGFBR2 inactivation following disruption of the Wnt-β-catenin pathway. We previously described CDX2P-G19Cre;Apcflox/flox mice, which is stochastically null for Apc in the colon epithelium. In this study, we generated CDX2P-G19Cre;Apcflox/flox;Tgfbr2flox/flox mice, with simultaneous loss of Apc and Tgfbr2. These mice developed tumors, including adenocarcinoma in the proximal colon. We compared gene expression profiles between tumors of the two types of mice using microarray analysis. Our results showed that the expression of the murine homolog of GSDMC was significantly upregulated by 9.25-fold in tumors of CDX2P-G19Cre;Apcflox/flox;Tgfbr2flox/flox mice compared with those of CDX2P-G19Cre;Apcflox/flox mice. We then investigated the role of GSDMC in regulating CRC tumorigenesis. The silencing of GSDMC led to a significant reduction in the proliferation and tumorigenesis of CRC cell lines, whereas the overexpression of GSDMC enhanced cell proliferation. These results suggested that GSDMC functioned as an oncogene, promoting cell proliferation in colorectal carcinogenesis. In conclusion, combined inactivation of both Apc and Tgfbr2 in the colon epithelium of a CRC mouse model promoted development of adenocarcinoma in the proximal colon. Moreover, GSDMC was upregulated by TGFBR2 mutation in CRC and promoted tumor cell proliferation in CRC carcinogenesis, suggesting that GSDMC may be a promising therapeutic target., Competing Interests: The authors have declared that no competing interests exist.

Background: KRAS gene mutations are found in 40-50% of colorectal cancer cases, but their functional contribution is not fully understood. To address this issue, we generated genetically engineered mice with colon tumors expressing an oncogenic Kras(G12D) allele in the context of the Adenomatous polyposis coli (Apc) deficiency to compare them to tumors harboring Apc deficiency alone., Methods: CDX2P9.5-G22Cre (referred to as G22Cre) mice showing inducible Cre recombinase transgene expression in the proximal colon controlled under the CDX2 gene promoter were intercrossed with Apc (flox/flox) mice and LSL-Kras (G12D) mice carrying loxP-flanked Apc and Lox-Stop-Lox oncogenic Kras(G12D) alleles, respectively, to generate G22Cre; Apc(flox/flox); Kras(G12D) and G22Cre; Apc(flox/flox); KrasWT mice. Gene expression profiles of the tumors were analyzed using high-density oligonucleotide arrays., Results: Morphologically, minimal difference in proximal colon tumor was observed between the two mouse models. Consistent with previous findings in vitro, Glut1 transcript and protein expression was up-regulated in the tumors of G22Cre;Apc (flox/flox) ; Kras(G12D) mice. Immunohistochemical staining analysis revealed that GLUT1 protein expression correlated with KRAS mutations in human colorectal cancer. Microarray analysis identified 11 candidate genes upregulated more than fivefold and quantitative PCR analysis confirmed that Aqp8, Ttr, Qpct, and Slc26a3 genes were upregulated 3.7- to 30.2-fold in tumors with mutant Kras., Conclusions: These results demonstrated the validity of the G22Cre; Apc(flox/flox) ;Kras (G12D) mice as a new mouse model with oncogenic Kras activation. We believe that this model can facilitate efforts to define novel factors that contribute to the pathogenesis of human colorectal cancer with KRAS mutations.

Objective: Increased expression of calcineurin in colorectal cancer (CRC) has been reported. Although the oncogenic function has been suggested, the clinical relevance is still unclear. We herein studied calcineurin expression as a prognostic biomarker in patients receiving curative surgery for stages I-III CRC., Methods: In 121 patients with stages I-III CRC treated at Hiroshima University between 1997 and 2003, calcineurin A expression was examined using immunohistochemistry (IHC) staining of surgical specimens. Specimens were considered positive for calcineurin A if any IHC-stained cells were observed within the carcinomatous area, and clinicopathological characteristics and survival outcomes were compared between IHC-positive and -negative groups., Results: Calcineurin A was preferentially expressed in the cytoplasm of cancer cells, and a median of 8% of the cells (range: 0-80%; interquartile range: 0-22.5%) were stained within the carcinomatous areas. Of 121 cases, 81 were determined as IHC positive while 40 were determined to be negative. Positive expression of calcineurin A, as well UICC-TNM stage, was associated with low relapse-free survival (RFS) rates in multivariate analyses (hazard ratio = 2.92; 95% CI: 1.27-7.92; p = 0.010)., Conclusion: Increased calcineurin A expression is associated with lower RFS rates and may have clinical value in predicting recurrence., (© 2016 S. Karger AG, Basel.)

Objective: Colorectal cancer (CRC) develops through the deregulation of gene expression and the accumulation of epigenetic abnormalities, leading to tumor cell acquisition of malignant features. MicroRNAs (miRNAs) play a critical role in cancer development, where they can act as oncogenes or oncosuppressors., Methods: miR-148a expression was measured by qRT-PCR in patients with colorectal adenoma (n = 21) and CRC (stage I-IV, n = 159) using formalin-fixed paraffin-embedded tissue samples. In situ hybridization (ISH) using an miR-148a-specific probe was also performed. To further confirm the direct effect of miR-148a on matrix metalloproteinase (MMP)7 expression in CRC, MTT and cell invasion assays using HT29 and WiDr cells were performed., Results: miR-148a expression was found to be clearly downregulated in high-grade adenoma compared to low-grade adenoma on both qRT-PCR and ISH analysis. Downregulation of miR-148a expression was significantly correlated with advanced clinicopathological features and was an independent prognostic classifier in patients with stage III CRC. In CRC cells and tissues, miR-148a expression was inversely correlated with the expression of MMP7., Conclusion: We showed the collaborative participation of miR-148a and MMP7 in CRC cell invasion. These results also demonstrate that the downregulation of miR-148a expression promotes CRC progression, especially carcinogenesis and cancer cell invasion., (© 2015 S. Karger AG, Basel.)

Staging classification of colorectal cancers is performed by the UICC/TNM classification system, which is the global gold standard. However, we often experience in clinical practice that there are considerable differences in prognoses between patients who have the same classification particularly in stage II and III cancers. The aim of this study was to propose a new TNM-G classification to predict prognosis and recurrence by supplementing the conventional TNM classification. A total of 220 cases of colorectal cancer, including 77 at stage II and 143 at stage III, were registered from four independent facilities. Immunohistochemical staining for 7 molecules, such as p53, vascular endothelial growth factor (VEGF)-A, VEGF-C, regenerating islet-derived family, member 4 (Reg IV), olfactomedin 4, Claudin-18 and matrix metalloproteinase-7 (MMP‑7), was performed to investigate the correlation between clinicopathological factors and expression of each molecule. Based on the results, no significant correlation was observed between the immunostaining expression of these 7 factors and recurrence in total colorectal cancer. Recurrence in stage II (77 cases) was significantly higher in cases positive for Reg IV expression (P=0.042). On analysis of overall survival (OS) and disease‑free survival (DFS), VEGF-C and Reg IV expression had a correlation with poor prognosis, therefore, these factors were selected and applied to G-factor classifications so that cases negative for both could be classified as G0, cases positive for either of the factors could be classified as G1, and cases positive for both factors could be classified as G2. While no significant correlation was observed in the recurrence rates between G0 and G2, OS and DFS in stage II cases were significantly poorer for G2 cases in comparison with G0 or G1 cases. The survival curves of OS and DFS in stage II G2 were similar to that of stage III cases. According to these results, prognosis of VEGF-C/Reg IV both positive G2 cases in stage II colorectal cancer was found to be almost equal to the poor survival in stage III cases, and the advancement of one stage up migration based on G-factors may be supposed to be highly feasible for clinical application. In conclusion, the combination of VEGF-C and Reg IV may be a promising factor for clinical staging to supplement the classical TNM classification system, and it may suggest a good indication of adjuvant chemotherapy for G2 cases in stage II colorectal cancers.

Aims: Olfactomedin 4 is a useful marker for stem cells in the intestine and is an independent prognostic molecule for survival in patients with colorectal cancer (CRC). Claudin-18, a component of tight junctions, correlates with poor survival in patients with CRC and is associated with the gastric phenotype. We investigated the possible usefulness of these molecules in serrated neoplasia of the colorectum., Methods and Results: We performed immunohistochemical analysis of colorectal polyps, including hyperplastic polyps (HP), sessile serrated lesions (SSL), traditional serrated adenomas (TSA) and conventional adenomas (CA). We also investigated the association between expression of these molecules and clinicopathological parameters in serrated adenocarcinoma (SAC) and non-SAC of the colorectum. Olfactomedin 4 expression was not detected or was decreased in SSL compared with the other polyp types. Claudin-18 expression was higher in SSL than in the other types. Similarly, positivity for olfactomedin 4 in SAC was significantly lower than that in non-SAC, and positivity for claudin-18 in SAC was significantly higher than that in non-SAC. Furthermore, claudin-18-positive SAC showed more advanced N grade and stage than claudin-18-negative SAC., Conclusions: Reduced expression of olfactomedin 4 and ectopic expression of claudin-18 might be useful markers in the differential diagnosis of serrated polyps., (© 2013 Blackwell Publishing Ltd.)

Claudin-18 plays a key role in constructing tight junctions, and altered claudin-18 expression has been documented in various human malignancies; however, little is known about the biological significance of claudin-18 in colorectal cancer (CRC). The aim of this study is to investigate the significance of claudin-18 expression in CRC and its association with clinicopathological factors. We performed clinicopathological analysis of claudin-18 expression in a total of 569 CRCs by immunohistochemistry. Moreover, we investigated the association between claudin-18 and various markers including gastric/intestinal phenotype (MUC5AC, MUC6, MUC2 and CD10), CDX2, claudin-3, claudin-4, p53 and Ki-67. Claudin-18 expression was detected in 21 of the 569 CRCs (4%) and was seen exclusively on the cell membrane. Positive expression of claudin-18 showed a significant correlation with positive expression of MUC5AC (P < 0.0001) and negative expression of CDX2 (P= 0.0013). The prognosis of patients with positive claudin-18 expression was significantly poorer than in negative cases (P= 0.0106). Multivariate analysis revealed that T grade, M grade and claudin-18 expression were independent predictors of survival in patients with CRC. We revealed that claudin-18 expression correlates with poor survival in patients with CRC and is associated with the gastric phenotype., (© 2010 The Authors. Pathology International © 2010 Japanese Society of Pathology and Blackwell Publishing Asia Pty Ltd.)

Signet-ring cell carcinoma (SRCC) is a unique subtype of adenocarcinoma that is characterized by abundant intracellular mucin accumulation and a crescent-shaped nucleus displaced toward one end of the cell. Identification of an SRCC's primary site is important for better planning of patient management because the treatment and prognosis differs markedly depending on the origin of the SRCC. In the present study, we analyzed the immunohistochemical characteristics of 94 cases of SRCC, including 21 cases of gastric SRCC, 16 of colorectal SRCC, 10 of breast SRCC, and 47 of pulmonary SRCC, with antibodies against Reg IV and claudin-18, which we previously identified as gastric cancer-related genes. We also tested known markers cytokeratin 7, cytokeratin 20, MUC2, MUC5AC, caudal-related homeobox gene 2 (CDX2), thyroid transcription factor-1, mammaglobin, gross cystic disease fluid protein 15, and estrogen receptor. All 21 cases of gastric SRCC and 16 cases of colorectal SRCC were positive for Reg IV, and the remaining SRCCs were negative. Eighteen of 21 (86%) gastric SRCCs and 6 of 16 (38%) colorectal SRCCs were positive for claudin-18, whereas another SRCCs were negative. In conclusion, Reg IV staining and claudin-18 staining can aid in diagnosis of gastrointestinal SRCC.

Objective: Regenerating islet-derived family, member 4 (regenerating gene type IV, Reg IV) is overexpressed in colorectal cancer (CRC). The aim of this study was to investigate the diagnostic utility of Reg IV determination in sera from patients with CRC., Methods: We examined the expression and distribution of Reg IV in CRC by immunohistochemistry and determined Reg IV levels in sera from patients with CRC by enzyme-linked immunosorbent assay., Results: Immunostaining revealed that 23 of 80 (29%) CRC cases were positive for Reg IV. CRC cases with metastatic recurrence in the liver showed more frequently Reg IV staining than those without (p = 0.0102). Patients with CRC showing Reg IV staining had a significantly worse survival than those without Reg IV staining (p = 0.0117). Preoperatively, serum Reg IV concentrations were not elevated in CRC patients at stage 0-III, being in contrast to the significantly increased preoperative levels in stage IV CRC patients with liver metastasis., Conclusion: These results suggest that Reg IV is a prognosticator for poor survival. Serum Reg IV concentration may predict CRC recurrence in the liver., ((c) 2008 S. Karger AG, Basel)

Colorectal carcinoma is one of the most common malignancies in the world, and its incidence has increased in recent years. We have reported that expression of hypoxia-inducible factor (HIF)-1alpha correlates with expression of vascular endothelial growth factor (VEGF), tumor stage, lymphatic invasion, venous invasion, and liver metastasis. It has also been reported that a single nucleotide polymorphism (SNP) in exon 12 of HIF-1alpha gene is present in renal cell carcinoma and head and neck squamous cell carcinoma patients. We investigated the C1772T polymorphism in colorectal cancer patients and healthy control subjects to clarify the mechanism of HIF-1alpha activation in colorectal carcinoma. The exon 12 genotype was not associated with sex or age. The distribution of HIF-1alpha genotypes in controls was 89 C/C (89%), 11 C/T (11%), and 0 T/T (0%). The distribution of HIF-1alpha genotypes in colorectal cancer patients was 100 C/C (100%), 0 C/T (0%), and 0 T/T (0%). The difference in genotype distribution between patients and control subjects was significant (p<0.0005). These results suggest that the C1772T polymorphism in HIF-1alpha is not involved in progression or metastasis of colorectal carcinoma.

Multivariate regression analysis has shown that Ki-67 labeling index in the mucosa adjacent to cancer was the most significant marker for colorectal cancer metastasis among several metastasis-related parameters according to our previous retrospective data base (7). We have performed a prospective study to ascertain whether Ki-67 labeling index in the mucosa adjacent to cancer is a useful preoperative diagnostic marker for colorectal cancer metastasis. In 182 registered cases colonoscopically biopsied, we performed surgical resection of the cancer in 37 adenocarcinoma cases, which were registered in the study. In 31 out of the 37 cases except for 6 cases with an insufficient amount of non-neoplastic mucosa, preoperative diagnosis for metastasis was performed using the Ki-67 cutoff line. The cutoff line was set at 15% according to our previous retrospective database. The preoperative diagnosis for metastasis was compared to the pathological findings of the resected specimen. The incidences of correct diagnosis for metastasis was 81% (25/31). There were 3 false positive cases and 3 false negative cases in Dukes' A-B and Dukes' C, respectively. The mean Ki-67 labeling index in the mucosa adjacent to cancer of Dukes' A-B and Dukes' C-D cases, except for the 6 misdiagnosed cases, was 7.4+/-5.0% and 29.9+9.8%, being significant at p<0.0001 by unpaired Mann-Whitney U test. These results suggest that Ki-67 labeling index in the mucosa adjacent to cancer might be a good marker for metastasis in colorectal cancer.

Interleukin 15 (IL-15 mRNA expression was detected in human colorectal cancer cells (Colo320, WiDr, TCO and DLD1) by the reverse transcriptase-polymerase chain reaction (RT-PCR). Only Colo320 and WiDr cells secreted IL-15 culture medium. With IL-15 treatment, all cell lines grew at a rate of 120-180% of that of nontreated cells. A binding assay with (125)I-labeled IL-15 showed binding activity to IL-15 in Colo320 (K(d): 0.098 nM) cells. IL-15 also reversed the growth inhibition caused by serum starvation in Colo320 cells. IL-15-induced cell growth in regular and serum-free media was abrogated by anti-IL-15 antibody treatment in Colo320 cells. Moreover, IL-15 treatment reduced doxorubicin-induced cytostasis and cytolysis in Colo320 cells by 50%. The invasion capacity of IL-15-treated Colo320 cells was 5.3 times that of untreated cells. Immunoblotting showed that IL-15-treated Colo320 cells exhibited downregulation of p21Waf1 and Bax, and upregulation of Bcl-2, phospho-AKT, MMP9/MMP2, and VEGF. Finally, immunostaining of human colon cancer revealed that 33 (70%) of 47 Dukes' C cases showed IL-15 expression in cancer cells, whereas only 16% of Dukes' B cases did (p < 0.0001). IL-15 may play important roles in cell proliferation, invasion, and metastasis of human colorectal cancer., (Copyright 2001 S. Karger AG, Basel)