[Primary pulmonary meningioma; report of a case]

Primary pulmonary meningiomas are quite rare, and their occurrence has been reported only sporadically. A 49-year-old, asymptomatic female was hospitalized for the evaluation of a coin lesion in the left lung radiography. She has no history of previous neoplasm or symptom referable to the central nervous system. Chest computed tomography (CT) demonstrated a 9 x 14 mm, round, noncalcified, well-demarcated lesion in the left upper lobe of the lung (S(1+2)). For diagnostic purposes, enucleation of the tumor was performed. The resected specimen revealed histologically classical typical meningioma. Because postoperative magnetic resonance imaging (MRI) of the brain did not show any intracranial mass, this case was and diagnosed as a primary pulmonary meningioma. The patient was discharged with no complication, and alive without recurrence of disease 14 months after surgery.

Micropapillary pattern: a distinct pathological marker to subclassify tumours with a significantly poor prognosis within small peripheral lung adenocarcinoma (<=20 mm) with mixed bronchioloalveolar and invasive subtypes (Noguchi's type C tumours)

AIMS

A micropapillary pattern (MPP) in lung adenocarcinoma, characterized by papillary structures with epithelial tufts lacking a central fibrovascular core, has been reported to be a new pathological marker of poor prognosis. However, its clinicopathological and prognostic significance in small lung adenocarcinomas (</=20 mm) remains undetermined. A new histological classification of small lung adenocarcinoma proposed by Noguchi et al. has been found to be useful since it has defined surgically curable bronchioloalveolar carcinoma (BAC)-type tumours (Noguchi's type A and B) based on the absence of active fibroblastic proliferation. However, BAC-type tumours with active fibroblastic proliferation (Noguchi's type C), which is adenocarcinoma with mixed subtypes including BAC and invasive carcinoma in the new World Health Organization (WHO) classification, account for most of the small adenocarcinomas and represent a heterogeneous group ranging from minimal to overtly invasive cancer with variable prognoses. Therefore, in this study the aim was to investigate whether MPP can be an additional histological marker(s) to subclassify this heterogeneous group in small lung adenocarcinoma.

METHODS AND RESULTS

One hundred and twenty-two cases of small lung adenocarcinomas (</=20 mm in maximum dimension) classified according to the new WHO classification and Noguchi's proposal were analysed with reference to the presence of MPP. Of the 122 cases, 67 (55%) were MPP-positive and 55 (45%) were MPP-negative. Lymph node metastasis and pleural invasion were significantly more frequent in the MPP-positive group: 74% and 66% in the positive group versus 26% and 34% in the negative group, respectively. The 5-year survival of the MPP-positive group was 54%, whereas that of the MPP-negative group was 81% (P=0.024). The 5-year survival rates of BAC (Noguchi's type A and B) (n=14), mixed BAC and invasive adenocarcinoma (Noguchi's type C) (n=85) and invasive adenocarcinoma (Noguchi's type D and F) (n=23) were 100%, 68% and 36%, respectively. In patients with mixed BAC and invasive adenocarcinoma (Noguchi's type C tumours), the 5-year survival of the MPP-positive group (n=51) was 54%, significantly lower than that of the MPP-negative group (n=23) of 100% (P=0.02).

CONCLUSIONS

MPP is a simple and distinct pathological marker to subclassify tumours with a significantly poor prognosis within small (</=20 mm) mixed BAC and invasive adenocarcinoma (Noguchi's type C tumours).

[A case of advanced gastric cancer with multiple liver metastases responding to TS-1 and CDDP]

A 44-year-old male presented to our hospital with abdominal pain. The upper endoscopy revealed advanced gastric cancer. On the abdominal CT, there was evidence of multiple, massive liver metastases. After total gastrectomy, the patient was treated with daily oral administration of 120 mg TS-1 for 4 weeks followed by 2 weeks' rest and 6 weekly infusions of 10 mg CDDP in an intra-hepatic artery as 1 cycle. On the follow-up CT, the liver metastases had decreased significantly both in size and number after 2 cycles. The current case suggests that TS-1 and CDDP may have a potent therapeutic efficacy in cases of advanced gastric cancer with multiple liver metastases.

Increased concentrations of human beta-defensins in plasma and bronchoalveolar lavage fluid of patients with diffuse panbronchiolitis

BACKGROUND

Human beta-defensin (HBD)-1 and -2 are antimicrobial peptides present in the respiratory tract. Recent reports have indicated reduced activity of beta-defensins in cystic fibrosis, suggesting that beta-defensins may play an important role in the pathological process of chronic respiratory tract infection. Diffuse panbronchiolitis (DPB) is a progressive disease characterised by frequent episodes of superimposed infection, typically caused by Pseudomonas aeruginosa. The aim of this study was to elucidate the role of these antimicrobial peptides in this disease.

METHODS

The concentrations of HBD-1 and HBD-2 in plasma and bronchoalveolar lavage (BAL) fluid from 33 patients with DPB and 30 normal adults were measured by radioimmunoassay. Localisation of HBD-2 was investigated immunohistochemically in an open lung biopsy specimen obtained from a patient with DPB.

RESULTS

High concentrations of HBD-1 and HBD-2 were noted in BAL fluid from DPB patients. Increased plasma concentrations of HBD-2, but not HBD-1, were found in patients with DPB compared with control subjects. In patients with DPB the HBD-2 concentration in BAL fluid correlated significantly with the numbers of cells recovered from the BAL fluid (total cells, neutrophils, and lymphocytes) and with the BAL fluid concentration of IL-1beta. Synthetic HBD-2, but not HBD-1, had dose dependent bactericidal activity against P aeruginosa. Treatment of 14 patients with macrolides significantly reduced BAL fluid concentrations of HBD-2 but not HBD-1 or plasma concentrations of HBD-1 and HBD-2. Immunohistochemistry of lung tissue showed localisation of HBD-2 in the epithelia of the distal bronchioles.

CONCLUSIONS

These results indicate that beta-defensins, particularly HBD-2, participate in antimicrobial defence in the respiratory tract in DPB, and that the BAL fluid concentration of HBD-2 may be a useful marker of airway inflammation in patients with DPB.

Sentinel lymph node detection with Tc-99m tin colloids in patients with esophagogastric cancer

BACKGROUND

The aim of this study was to determine by radioisotope use whether the sentinel lymph node concept is applicable to esophagogastric cancers. In addition, we examined radioactivities of hot nodes and compared them with the sensitivity of a gamma probe.

METHODS

The subjects were 44 patients, 23 with esophageal cancer and 21 with gastric cancer. The day before surgery, patients underwent endoscopic submucosal injection of 184 MBq of Tc-99m tin colloids into sites surrounding the tumor. Radioisotope activities of lymph nodes dissected at surgery were measured with a well-typed gamma detector and each lymph node was categorized as a hot or cold node. Histopathology of the lymph nodes was examined by hematoxylin and eosin staining. Radioisotope activities and histopathological results were compared to determine whether radioisotope flow reflects lymphatic flow to regional lymph nodes. The sensitivity of a gamma probe was measured in a laboratory study and the relation between the radioisotope activities of hot nodes and the detection sensitivity of the gamma probe was examined.

RESULTS

Histopathological examination revealed lymph node metastasis in 18 of the 44 patients. In 15 of these 18 patients, metastatic foci were recognized in at least one hot node. Subsequent analysis was performed on the 36 patients in whom tumor invasion was confined to the muscle layer and in whom endoscopic clippings had not been applied. Lymph node metastases were observed in 12 of these 36 patients. In these 12 patients, at least one hot node was positive for metastasis. The laboratory study revealed that the gamma probe was able to detect radioisotope activities of >/=0.02 micro Ci. Thirty-two of 63 (51%) esophageal cancer hot nodes and 16 of 86 (19%) gastric cancer hot nodes showed radioisotope activities below the detection sensitivity of the gamma probe.

CONCLUSION

The sentinel lymph node concept is applicable to patients with esophageal and gastric cancers; however, further studies are necessary to identify hot nodes accurately using gamma probes.

The correlation between 99mTc-MIBI uptake and MIB-1 as a nuclear proliferation marker in glioma--a comparative study with 201Tl

Technetium-99m methoxy-isobutylisonitrile (MIBI), like thallium-201 (201Tl), is a highly efficient agent for the diagnosis and monitoring of glioma tumors. Although 201Tl uptake is known to be partly associated with proliferative activity, little is known about the correlation between MIBI uptake and proliferation activity in gliomas. The current study was performed to assess the correlation between MIBI uptake and proliferative activities in gliomas, estimated by the monoclonal antibody to Ki-67 antigen (MIB-1) staining method. By comparing the results with those of 201Tl, we determined which tracer would be suitable for estimating proliferative activities. Twenty-four presurgical glioma patients (six with low-grade gliomas, five with anaplastic astrocytomas, and 13 with glioblastomas) were given MIBI and 201Tl SPECT. Early (10 min after injection) and delayed images (3 h after injection) were obtained for both MIBI and 201Tl scintigraphy. SPECT parameters, early ratio (ER), delayed ratio (DR), and retention index (RI) were obtained in both radiopharmaceuticals. All patients underwent subsequent surgical excision, and the specimens were immunostained for MIB-1. The proliferative activity was measured as a percentage positive nuclear area for MIB-1 (MI; MIB-1 index). To evaluate the relationship between the proliferative activity and SPECT parameters, we performed a correlation analysis. MI correlated with the MIBI uptake ratio (r = 0.75 for ER, and r = 0.7 for DR). Both DR and RI of 201Tl also correlated with MI, but weakly (r = 0.6 for DR, and. r = 0.59 for RI). There was no significant correlation between the MIB-1 index and the other parameters. MIBI-uptake parameters demonstrated a stronger positive correlation with the MIB-1 index than that of 201Tl. With the use of MIBI SPECT, we can estimate the proliferative activity of glioma noninvasively.

Sugar-pendant diamines

A set of 1,3-propanediamine derivatives connected to carbohydrates (5) has been prepared in four steps from peracetylated sugar and 1,3-dibromo-2-propanol in 60-73% yields. D-Glucose, D-mannose, D-galactose, D-xylose, D-ribose, and maltose are utilized as sugar molecules in this work. The diamine moiety was connected to the C1 carbon of the glycopyranose ring via an O-glycoside bond. All of the anomeric configurations and sugar puckering conformations, except in the D-maltose derivative, were determined by X-ray crystallography of the diazido or dibromo precursors. While glycosidation of peracetylated galactopyranose with 1,3-dibromo-2-propanol in the presence of boron trifluoride afforded both anomers, the neighboring group participation of the 2-acetoxy group yielded a single anomer for the other substrates. This method has been used to synthesize a library of sugar-pendant diamines including an OH-protected derivative (6), and an N,N'-diisopropyl-substituted derivative (7). A similar series of reactions using 2,3-dibromo-1-propanol gave ethylenediamine-type derivatives (11), and bis(bromomethyl)bis(hydroxymethyl)methane (12) gave bisglucose-pendant derivatives (16).

Comprehensive isolation of meiosis-specific genes identifies novel proteins and unusual non-coding transcripts in Schizosaccharomyces pombe

In order to isolate meiosis-specific genes in Schizosaccharomyces pombe, we have constructed a subtracted cDNA library enriched in clones whose expression is enhanced during meiosis induced by nitrogen starvation. Using northern blot analysis, we isolated 31 kinds of clones whose expression was induced in a meiosis/sporulation-specific manner. We comprehensively named them meu after meiotic expression upregulated. The transcription of 20 meu genes was found to be dependent on the mei4(+) gene, which encodes a transcription factor required for the progression of meiosis. DNA sequencing indicated that most of the meu genes encode novel proteins. Notably, five of the meu genes harbor no apparent protein coding sequences, and the transcripts form stable hairpin structures, suggesting that they may generate non-coding RNAs or antisense RNAS: The results presented here imply that RNAs are also important for the comprehensive characterization of genomic expression.

Tubal ectopic pregnancy associated with an adenomatoid tumor

We present a case of coexistence of an ectopic pregnancy and an adenomatoid tumor in the same fallopian tube. The adenomatoid tumor is the most common benign neoplasm of the fallopian tube, and the vast majority of ectopic pregnancies occur in the fallopian tube. However, coexistence of these two conditions is extremely rare, and there has been only one previously reported case in the English literature. In the present case, the placental tissue, consisting of chorionic villi and decidua, was present in the ampulla, and the adenomatoid tumor was found in the myosalpinx, just proximal to the implantation site, replacing a large part of the myosalpinx. The close spatial relationship of these two lesions suggests that an adenomatoid tumor could have interfered with transportation of the fertilized ovum through the tube, possibly via impaired contractile activity of the myosalpinx, and consequently caused the ectopic tubal pregnancy.

Regulation of fibronectin expression and splicing in migrating epithelial cells: migrating MDCK cells produce a lesser amount of, but more active, fibronectin

Previously we have demonstrated that in MDCK epithelial cells not only transforming growth factor-beta (TGF-beta) but also hepatocyte growth factor/scatter factor (HGF/SF) regulates fibronectin (FN) splicing by increasing the ratio of EDA-containing FN (EDA+ FN) mRNA to EDA-minus FN (EDA- FN) mRNA (EDA+/EDA- ratio). EDA+ FN is known to be upregulated in tissues where cells actively migrate, such as those during morphogenesis, wound healing, and tumorigenesis. However, a direct association between cell migration and FN splicing at the EDA region has never been investigated. In this work, we have shown by using an in vitro wound migration assay that migrating epithelial cells regulate FN production and splicing differently compared to nonmigrating cells. Wounds were introduced as migration stimuli into the 10-day-old confluent cell sheet, where the EDA+/EDA- ratio and FN mRNA expression levels were stable. In migrating cells at the wound edge, the FN mRNA level decreased by 0.73-fold and the EDA+/EDA- ratio increased by 1.32-fold when compared with nonmigrating cells apart from the wound edge. HGF/SF significantly stimulated cell migration at the wound edge and concomitantly decreased the FN mRNA level by 0.60-fold and increased the EDA+/EDA- ratio by 1.84-fold in migrating cells. In nonmigrating cells apart from the wound edge, FN mRNA expression and splicing were not influenced by either wound stimulation or HGF/SF. EDA+ FN stimulates cell migration more effectively than EDA- FN and thus is considered to be a more active variant of FN. Taken together, migrating MDCK cells appear to regulate FN mRNA expression and splicing to produce a lesser amount of, but more active, FN.

Brain surface ependymoma

A case of brain surface ependymoma is reported here. A 41-year-old woman presented with weakness of the right upper limb. Magnetic resonance imaging revealed a left fronto-parietal cystic tumor with a calcified mural nodule. Total removal of the tumor was performed. This tumor was located within the surface portion of the fronto-parietal parenchyma and was sharply demarcated from the surrounding brain tissue, and there was no continuity with the ventricles. Histological examination of this tumor showed monotonous proliferation of tumor cells with moderate cellularity and occasional mitoses, forming true ependymal rosettes and perivascular pseudorosettes with fibrillary background. A clear cell component resembling oligodendroglioma was partly noted. The tumor cells showed positive immunoreaction for glial fibrillary acid protein and vimentin.

Expression of emmprin (CD147), a cell surface inducer of matrix metalloproteinases, in normal human brain and gliomas

EMMPRIN (extracellular matrix metalloproteinase inducer), also called CD147, basigin or M6 in the human, is a member of the immunoglobulin superfamily that is present on the surface of tumor cells and stimulates adjacent fibroblasts to produce matrix metalloproteinases (MMPs). In our study, we investigated expression of EMMPRIN in human normal brain and gliomas, since mouse basigin and chicken HT7, the species homologues of human EMMPRIN, are associated with neuronal interactions and normal blood-brain barrier function, respectively. EMMPRIN expression was detected in all samples of non-neoplastic brain and glioma tissues examined. However, expression levels of EMMPRIN mRNA and protein were significantly higher in gliomas than in non-neoplastic brain. Moreover, levels of mRNA expression and immunohistochemical staining correlated with tumor progression in gliomas: They were highest in the most malignant form of glioma, glioblastoma multiforme, followed by anaplastic astrocytoma and then low-grade astrocytoma. Also, immunolocalization revealed quite different distributions in non-neoplastic brain and glioma: EMMPRIN was demonstrated only in vascular endothelium in non-neoplastic regions of the brain, whereas it was present in tumor cells but not in proliferating blood vessels in malignant gliomas. These data indicate that an MMP inducer molecule EMMPRIN is differently expressed in human normal brain and gliomas and could be associated with astrocytoma progression. Possible mechanisms whereby glioma cell EMMPRIN could influence tumor progression will be discussed.

E-cadherin and cadherin-associated cytoplasmic proteins are expressed in murine mast cells

Cadherins, calcium-dependent cell adhesion molecules, play crucial roles, not only in the maintenance of tissue integrity, but also in the regulation of many aspects of cell behavior. We investigated the expression of "classic" E-, N- and P-cadherins in bone marrow-derived cultured mast cells (BMMC) and peritoneal mast cells (PMC) from mice. Flow cytometric analysis and immunocytochemical staining indicated that E-cadherin was expressed on the cell surface of BMMC and also at lower levels on PMC. N-cadherin was also expressed on the surface of BMMC, but not of PMC, whereas P-cadherin expression was seen in neither cell type. Significant expression of E- and N-cadherin mRNA was observed in BMMC by reverse transcriptase-polymerase chain reaction (RT-PCR), but PMC expressed only E-cadherin mRNA. Western blotting analysis indicated expression of alpha- and beta-catenins and p120-catenin (or p120 cas) in BMMC, whereas PMC showed less intense expression of alpha- and beta-catenins with high levels of p120 expression. Analyses of beta-catenin or E-cadherin immunoprecipitates from BMMC lysate revealed that alpha-catenin, beta-catenin, and E-cadherin were co-precipitated, suggesting that E-cadherin and catenins form a complex in mast cells. Addition of a blocking antibody of homophilic E-cadherin interactions, or a synthetic E-cadherin-binding decapeptide containing the histidine-alanine-valine (HAV) sequence in methylcellulose cultures of gut intraepithelial mononuclear cells or BMMC, significantly suppressed the clonal growth of mast cells. Furthermore, the blocking antibody or synthetic decapeptide significantly suppressed BMMC adhesion to E-cadherin-expressing F9 cell monolayers. These results indicated that E-cadherin and associated cytoplasmic proteins in mast cells might be involved in the regulation of certain stages of mast cell differentiation and cell-cell interactions.

Glioma cell extracellular matrix metalloproteinase inducer (EMMPRIN) (CD147) stimulates production of membrane-type matrix metalloproteinases and activated gelatinase A in co-cultures with brain-derived fibroblasts

Extracellular matrix metalloproteinase inducer (EMMPRIN) also called CD147, basigin or M6 in the human is a member of the immunoglobulin superfamily that is enriched on the surface of tumor cells and stimulates adjacent stromal cells to produce several matrix metalloproteinases (MMPs). In this study, we have demonstrated that coculturing of EMMPRIN-expressing human glioblastoma multiforme cells (U251) with brain-derived human fibroblasts not only stimulates production, but also activation of pro-gelatinase A (proMMP-2), an enzyme that is enriched in malignant gliomas and most likely crucial to tumor progression. Production of membrane types 1 and 2-MMPs (MT1-MMP and MT2-MMP), which are activators of proMMP-2, was also stimulated in these cocultures. Stimulation of MMP-2, MT1-MMP and MT2-MMP production was inhibited by anti-EMMPRIN monoclonal antibody in a dose-dependent manner. Thus, we have shown, for the first time, that EMMPRIN causes increased expression of MT1-MMP and MT2-MMP, as well as increased production and activation of MMP-2.

Dmc1 of Schizosaccharomyces pombe plays a role in meiotic recombination

We report here a Schizosaccharomyces pombe gene (dmc1(+)) that resembles budding yeast DMC1 in the region immediately upstream of the rad24(+) gene. We showed by northern and Southern blot analysis that dmc1(+) and rad24(+) are co-transcribed as a bicistronic mRNA of 2.8 kb with meiotic specificity, whereas rad24(+) itself is constitutively transcribed as a 1.0-kb mRNA species during meiosis. Induction of the bicistronic transcript is under the control of a meiosis-specific transcription factor, Ste11. Disruption of both dmc1(+) and rad24(+) had no effect on mitosis or spore formation, and dmc1Delta cells displayed no change in sensitivity to UV or gamma irradiation relative to the wild type. Tetrad analysis indicated that Dmc1 is involved in meiotic recombination. Analysis of gene conversion frequencies using single and double mutants of dmc1 and rhp51 indicated that both Dmc1 and Rhp51 function in meiotic gene conversion. These observations, together with a high level of sequence identity, indicate that the dmc1(+) gene of S. POMBE: is a structural homolog of budding yeast DMC1, sharing both similar and distinct functions in meiosis.

Front-cell-specific expression of membrane-type 1 matrix metalloproteinase and gelatinase A during cohort migration of colon carcinoma cells induced by hepatocyte growth factor/scatter factor

Migration of tumor cells is usually assessed as single cell locomotion in vitro using Boyden chamber type assays. In vivo, however, carcinoma cells frequently invade the surrounding tissue as coherent clusters or nests of cells. We have called this type of movement "cohort migration" and developed a two-dimensional in vitro cohort migration model, in which human rectal well-differentiated adenocarcinoma cells (L-10) migrate from piled-up cell islands as coherent sheets of cells when stimulated with hepatocyte growth factor/scatter factor. In this study, we examined whether there is a cohort migration-specific way of expression of matrix metalloproteinases (MMP) and whether degradation of extracellular matrix is necessary for this type of migration. Production of membrane-type 1-MMP (MT1-MMP) and gelatinase A (MMP-2) by L-10 cells was demonstrated by gelatin zymography, immunoblotting, and reverse transcription-PCR. When cohort migration was induced with hepatocyte growth factor/scatter factor, MT1-MMP and MMP-2 were immunolocalized predominantly in the leading edges of the front cells of migrating cell sheets, with the following cells being negative. In addition, during the cohort migration on gelatin-coated substratum, the gelatin matrix was degraded by the cells, in a very organized manner, causing radially arrayed lysis of gelatin matrix at the sites of leading edges. BB94, a synthetic inhibitor specific to MMPs, tissue inhibitor of metalloproteinases-1 and -2, and the COOH-terminal hemopexin-like domain of MMP-2 inhibited the migration on gelatin matrix. Thus, these data demonstrate that gelatin matrix is reorganized to suit cell migration via leading-edge-of-front-cell-specific localization of MT1-MMP and MMP-2 during cohort migration and suggest that the reorganization is essential for this type of migration.

Primary vaginal adenocarcinoma arising from the metanephric duct remnant

Primary vaginal adenocarcinoma unrelated to in utero exposure to diethylstilbestrol (DES) is very uncommon. We report a case of 65-year-old Japanese woman who presented with primary adenocarcinoma in the anterior wall of the vagina, where the left ureter-like metanephric duct remnant abnormally terminated. Histological examination in serial sections revealed the direct connection between the carcinoma and the metanephric duct remnant. Moreover, the remnant epithelium showed varying degrees of dysplastic changes, including carcinoma in situ in close proximity to the carcinoma. This patient also had a bicornate uterus and left renal aplasia. To our knowledge, this is the first reported case of a primary vaginal adenocarcinoma arising from the metanephric duct remnant. Although the precise mechanism involved in carcinogenesis in this clinicopathological setting remains unknown, adenocarcinoma should be included in the differential diagnosis of vaginal tumors in patients with renal aplasia and/or an ectopic termination of the ureter or metanephric duct remnant, especially when the tumor is in the anterior wall.

Solitary fibrous tumor of the vagina

The solitary fibrous tumor (SFT) is a rare tumor that most commonly arises in the pleura. Recent evidence has indicated that this tumor originates from mesenchymal, probably fibroblastic, cells and is not restricted to the pleura. However, its occurrence in the female genital tract is extremely rare. We report a case of primary SFT that originated from the vagina in a 34-year-old female. It was a pedunculated polypoid tumor and occurred at the site of scar tissue, caused by laceration during her last labor 7 years previously. Histologically, the tumor was predominantly composed of a random proliferation of spindle cells, intimately admixed with collagen. Immunohistochemically, the cells were strongly positive for CD34, vimentin and bcl-2, but were negative for S-100 protein, neuron-specific enolase, smooth muscle actin, desmin, CD68, cytokeratins and epithelial membrane antigen. To the best of our knowledge, this is the first reported case of a primary vaginal SFT in the English literature. Our report suggests to include SFT in the differential diagnosis of a spindle cell neoplasm originating from the vagina.

Conserved expression of hepatocyte growth factor activator inhibitor type-2/placental bikunin in human colorectal carcinomas

Hepatocyte growth factor activator inhibitor type 2 (HAI-2) was recently identified as a potent inhibitor of hepatocyte growth factor activator. It was also independently reported as placental bikunin (PB) and as a protein over-expressed in pancreatic cancer. The expression of HAI-2/PB was analyzed in human normal colon mucosa, adenomas, and carcinomas. HAI-2/PB mRNA was consistently expressed in the colorectal mucosa. The expression was conserved in the neoplastic colorectal mucosa, and no relationship was found between HAI-2/PB mRNA levels and tumor stages. Moreover, 13 out of 14 colorectal carcinoma cell lines expressed HAI-2/PB mRNA. Immunohistochemically, HAI-2/PB proteins were predominantly stained beneath the apical surface of normal enterocytes. In tumor tissues, rather disarranged intracytoplasmic granular staining was observed. The HAI-2/PB immunoreactivity was well conserved in the colonic adenoma-carcinoma sequence, and this protein may have important unknown function in the intestinal mucosa.