Exosomal microRNA in serum is a novel biomarker of recurrence in human colorectal cancer.

BACKGROUND: Functional microRNAs (miRNAs) in exosomes have been recognised as potential stable biomarkers in cancers. The aim of this study is to identify specific miRNAs in exosome as serum biomarkers for the early detection of recurrence in human colorectal cancer (CRC). METHODS: Serum samples were sequentially obtained from six patients with and without recurrent CRC. The miRNAs were purified from exosomes, and miRNA microarray analysis was performed. The miRNA expression profiles and copy number aberrations were explored using microarray and array CGH analyses in 124 CRC tissues. Then, we validated exosomal miRNAs in 2 serum sample sets (90 and 209 CRC patients) by quantitative real-time RT-PCR. RESULTS: Exosomal miR-17-92a cluster expression level in serum was correlated with the recurrence of CRC. Exosomal miR-19a expression levels in serum were significantly increased in patients with CRC as compared with healthy individuals with gene amplification. The CRC patients with high exosomal miR-19a expression showed poorer prognoses than the low expression group (P<0.001). CONCLUSIONS: Abundant expression of exosomal miR-19a in serum was identified as a prognostic biomarker for recurrence in CRC patients.

Circulating tumour cell-derived plastin3 is a novel marker for predicting long-term prognosis in patients with breast cancer.

BACKGROUND: Identification of promising biomarkers that predict the prognosis of patients with breast cancer is needed. In this study, we hypothesised that the expression of the epithelial-mesenchymal transition-related biomarker plastin3 (PLS3) in peripheral blood could be a prognostic factor in breast cancer. METHODS: We examined PLS3 expression in breast cancer cell lines with epithelial and mesenchymal traits and in circulating tumour cells (CTCs) obtained from the peripheral blood of breast cancer patients. We investigated PLS3 expression in the peripheral blood of 594 patients with breast cancer to evaluate the clinical significance of PLS3 expression. RESULTS: Robust PLS3 expression was observed in different breast cancer cell lines (Hs578t, MCF-7, MDA-MB-468, and MDA-MB-231) as well as in a bone marrow derived cancer cell line (BC-M1). In both the training (n=298) and validation (n=296) sets, PLS3 expression was observed in CTCs of patients with breast cancer. PLS3-positive patients showed significantly poorer overall and disease-free survival than PLS3-negative patients (P=0.0001 and 0.003, respectively). Subset analysis revealed that this prognostic biomarker was relevant in patients with stage I-III cancer, particularly in patients with luminal-type and triple-negative-type tumours. CONCLUSIONS: These data demonstrated that PLS3 was expressed in CTCs undergoing the epithelial-mesenchymal transition in patients with breast cancer. Furthermore, PLS3 may be an excellent biomarker for identifying groups at risk of recurrence or with a poor prognosis.

Identification of a bona fide microRNA biomarker in serum exosomes that predicts hepatocellular carcinoma recurrence after liver transplantation.

BACKGROUND: Predictive biomarkers for the recurrence of hepatocellular carcinoma (HCC) have great benefit in the selection of treatment options, including liver transplantation (LT), for HCC. The purpose of this study was to identify specific microRNAs (miRs) in exosomes from the serum of patients with recurrent HCC and to validate these molecules as novel biomarkers for HCC recurrence. METHODS: We employed microarray-based expression profiling of miRs derived from exosomes in the serum of HCC patients to identify a biomarker that distinguishes between patients with and without HCC recurrence after LT. This was followed by the validation in a separate cohort of 59 HCC patients who underwent living related LT. The functions and potential gene targets of the recurrence-specific miRs were analysed using a database, clinical samples and HCC cell lines. RESULTS: We found that miR-718 showed significantly different expression in the serum exosomes of HCC cases with recurrence after LT compared with those without recurrence. Decreased expression of miR-718 was associated with HCC tumour aggressiveness in the validated cohort series. We identified HOXB8 as a potential target gene of miR-718, and its upregulation was associated with poor prognosis. CONCLUSION: Circulating miRs in serum exosomes have potential as novel biomarkers for predicting HCC recurrence.

Amplification of PVT-1 is involved in poor prognosis via apoptosis inhibition in colorectal cancers.

BACKGROUND: We previously conducted gene expression microarray analyses to identify novel indicators for colorectal cancer (CRC) metastasis and prognosis from which we identified PVT-1 as a candidate gene. PVT-1, which encodes a long noncoding RNA, mapped to chromosome 8q24 whose copy-number amplification is one of the most frequent events in a wide variety of malignant diseases. However, PVT-1 molecular mechanism of action remains unclear. METHODS: We conducted cell proliferation and invasion assays using colorectal cancer cell lines transfected with PVT-1siRNA or negative control siRNA. Gene expression microarray analyses on these cell lines were also carried out to investigate the molecular function of PVT-1. Further, we investigated the impact of PVT-1 expression on the prognosis of 164 colorectal cancer patients by qRT-PCR. RESULTS: CRC cells transfected with PVT-1 siRNA exhibited significant loss of their proliferation and invasion capabilities. In these cells, the TGF-ß signalling pathway and apoptotic signals were significantly activated. In addition, univariate and multivariate analysis revealed that PVT-1 expression level was an independent risk factor for overall survival of colorectal cancer patients. CONCLUSION: PVT-1, which maps to 8q24, generates antiapoptotic activity in CRC, and abnormal expression of PVT-1 was a prognostic indicator for CRC patients.

Paired related homoeobox 1, a new EMT inducer, is involved in metastasis and poor prognosis in colorectal cancer.

BACKGROUND: Paired related homoeobox 1 (PRRX1) has been identified as a new epithelial-mesenchymal transition (EMT) inducer in breast cancer. However, the function of PRRX1 in colorectal cancer (CRC) has not been elucidated. METHODS: We utilised ectopic PRRX1-expressing cell lines to analyse the function of PRRX1 in CRC. The clinical significance of PRRX1 was also examined on three independent CRC case sets. RESULTS: PRRX1 induced EMT and the stem-like phenotype in CRC cells. In contrast to studies of breast cancer, abundant expression of PRRX1 was significantly associated with metastasis and poor prognosis in CRC. CONCLUSION: PRRX1 is an indicator of metastasis and poor prognosis in CRC cases. Further investigation is required to uncover the signalling network regulating PRRX1.

Clinical significance of miR-144-ZFX axis in disseminated tumour cells in bone marrow in gastric cancer cases.

BACKGROUND: We previously reported that bone marrow (BM) was a homing site for gastric cancer (GC) cells leading to haematogenous metastases. There has been little study that microRNAs regulated pathways in malignant cells or host cells in BM, and thereby regulated the progression of GC. METHODS: Both microRNA microarray and gene expression microarray analyses of total RNA from BM were conducted, comparing five early and five advanced GC patients. We focused on miR-144-ZFX axis as a candidate BM regulator of GC progression and validated the origin of the microRNA expression in diverse cell fractions (EpCAM(+)CD45(-), EpCAM(-)CD45(+), and CD14(+)) by magnetic-activated cell sorting (MACS). RESULTS: Quantitative reverse-transcriptase (RT)-PCR analysis validated diminished miR-144 expression in stage IV GC patients with respect to stage I GC patients (t-test, P=0.02), with an inverse correlation to ZFX (ANOVA, P<0.01). Luciferase reporter assays in five GC cell lines indicated their direct binding and validated by western blotting. Pre-miR144 treatment and the resultant repression of ZFX in GC cell lines moderately upregulated their susceptibility to 5-fluorouracil chemotherapy. In MACS-purified BM fractions, the level of miR-144 expression was significantly diminished in disseminated tumour cell fraction (P=0.0005). Diminished miR-144 expression in 93 cases of primary GC indicated poor prognosis. CONCLUSION: We speculate that disseminated cancer cells could survive in BM when low expression of miR-144 permits upregulation of ZFX. The regulation of the miR-144-ZFX axis in cancer cells has a key role in the indicator of the progression of GC cases.

Inflammatory pseudotumor of the liver in association with spilled gallstones 3 years after laparoscopic cholecystectomy: report of a case.

We report on a case of a female patient diagnosed with inflammatory pseudotumor of the liver in association with spilled gallstones 3 years after laparoscopic cholecystectomy for calculous acute cholecystitis. She was asymptomatic, but CT revealed an intrahepatic mass and two other extrahepatic masses between the liver and the diaphragm. Furthermore, diffusion-weighted MRI and PET suggested all three lesions could be malignant tumors. As the preoperative diagnosis was intrahepatic cholangiocellular carcinoma with peritoneal disseminations, we performed a posterior segmentectomy of the liver combined with partial resection of the diaphragm. Histological examination showed the intrahepatic tumor was an inflammatory granuloma with abscess formations. There were bilirubin stones between the liver and the diaphragm. Therefore, the tumor was diagnosed as inflammatory pseudotumor of the liver in association with spilled gallstones. In conclusion, the liver tumor emerged after laparoscopic cholecystectomy and may involve inflammatory pseudotumor of the liver in association with spilled gallstones.

Overexpression of HRad17 mRNA in human breast cancer: correlation with lymph node metastasis.

PURPOSE: A novel human gene, designated HRad17, was identified as the human homologue of the Rad17 of Schizosaccharomyces pombe and Rad24 of Saccharomyces cerevisiae. In yeast, these genes play a critical role in maintaining genomic stability. The aim of this study was to evaluate the expression of HRad17 in human breast cancer. EXPERIMENTAL DESIGN: We investigated HRad17 mRNA expression in 64 cases of human breast cancer by means of reverse-transcription-PCR, in situ hybridization, and immunohistochemistry. RESULTS: The HRad17 mRNA was overexpressed in 35 cases (54.7%). Twenty-four (68.6%) of 35 cases with HRad17 overexpression in cancer tissues were node-positive, whereas only 8 (27.6%) of 29 cases without HRad17 overexpressions were node-positive. The expression of HRad17 mRNA correlated with both lymph node metastasis (P = 0.001) and high Ki67 labeling index (P = 0.006). Although not significantly different, expression of HRad17 mRNA tended to correlate with tumor size (P = 0.06) and expression of mutant p53 protein (P = 0.10). Furthermore, expression of HRad17 mRNA was an independent predictor of axillary lymph node metastasis as well as of lymphatic permeation by multivariate analysis (P < 0.0001). CONCLUSIONS: Our study demonstrates that HRad17 might be related to the development of lymph node metastasis in human breast cancers. Although its function still remains unclear, the expression of HRad17 mRNA could open up a new window for the diagnostic staging and treatment of human breast cancers.

Clinical significance of K-Ras mutations in intraoperative tumor drainage blood from patients with colorectal carcinoma.

BACKGROUND: Recurrent and metastatic carcinoma of the colorectum remains a major problem. This may be ascribed to the presence of micrometastasis at diagnosis. The purpose of this study was to analyze prospectively the clinical value of detecting K-ras mutations in the perioperative circulating blood from patients with colorectal carcinoma. METHODS: Twenty-four patients whose tumor carried mutations in codon 12 of the K-ras gene were studied for the presence of cancer cells in perioperative blood samples, in particular, tumor drainage samples. A detection assay using CD45 immunomagnetic separation plus nested mutant allele specific amplification (MASA) was performed. RESULTS: K-ras mutations in CD45 negative cells in tumor drainage blood were detected in 7 (29.2%) of 24 patients. There was no significant relationship between the presence of a K-ras mutation and clinicopathological features. Four (57.1%) of the seven patients with a positive K-ras mutation in drainage blood had early recurrent disease. Of the 17 patients with no K-ras mutation, none developed metastatic disease. The recurrence rate of the K-ras mutation positive group was higher than that of the K-ras mutation negative group (P < .01). There was a significant difference, regarding prognosis, between K-ras mutation positive and negative groups (P < .01). CONCLUSIONS: This preliminary study demonstrates that the detection of circulating cancer cells in the tumor drainage blood by our new assay system may provide a predictor of recurrence and metastasis of colorectal cancer.

A novel isoform of human fibroblast growth factor 8 is induced by androgens and associated with progression of esophageal carcinoma.

Human esophageal carcinomas occur more frequently in males, suggesting that androgens may play a role in the regulation of gene expression associated with malignant transformation. We previously established an androgen-sensitive squamous cell carcinoma line, KSE-1, from a male patient with esophageal cancer; recently a novel isoform of human fibroblast growth factor 8 (FGF8f, isoform FGF8b) was identified and expressed following androgen stimulation of KSE-1 cells. The predicted amino acid sequence of FGF8f contained an additional 29 amino acids when compared to FGF8b. Flutamide, an androgen antagonist, inhibited both FGF8b and FGF8f transcription in a dose-dependent manner. Tissue analysis from tumors revealed FGF8b expression in 24 of 41 male, but in 0 of 9 female esophageal carcinomas (58.5%), and none in adjacent normal esophageal mucosa. In addition, FGF8f was detected in 9 of 24 FGF8b-positive tumors (37.5%), and this observation was significantly associated with a poor prognosis (P < 0.001). Our observations suggest that androgenic exposure will induce FGF isoforms in tumor cells, and expression of these growth factors is associated with the prevalence and prognosis of esophageal carcinoma in males.

Heparanase expression in clinical digestive malignancies.

Recently, mammalian heparanase was cloned, and its probable function in tumor progression was reported. However, its expression in human clinical cancers has not been fully studied. Thus we determined the heparanase mRNA expression in 30 esophageal cancer cell lines and 144 clinical samples including 38 esophageal squamous cell carcinomas, 71 gastric adenocarcinomas, and 35 colorectal adenocarcinomas. The fresh surgical specimens of cancer tissue (T) and its paired normal tissue (N) were used. The heparanase mRNA was evaluated by reverse transcriptase-polymerase chain reaction, and the T/N expression ratio was determined in clinical cases. All 30 esophageal cancer cell lines expressed heparanase mRNA. The T/N ratio was determined as high (> or =1.3), equal (0.8 approximately 1.2) or low (< or = 0.7) in each clinical case. In cases of esophageal cancer, 7 showed high, 10 equal and 21 low expression. In cases of colorectal cancer, 3 showed high, 16 equal and 16 low expression. On the other hand, 42 showed high, 22 equal and 7 low expression in cases of gastric cancer. The frequency of high expression cases was greater in gastric cancer than in esophageal or colorectal cancers (p < 0.05). There were no differences in clinicopathologic factors including prognosis between high and low expression cases of each cancer. Our mRNA study of heparanase indicated that its expression status was different among gastrointestinal cancers. The clinical and pathological impact was low compared to other proteinases, although further studies are recommended for final conclusion.

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.

Genetic polymorphism of N-acetyltransferase 2 in patients with esophageal cancer.

OBJECTIVE: N-Acetylation polymorphism is a representative genetic trait related to an individual's susceptibility to several cancers. However, there remains a controversy and no consensus concerning whether there is a true association between esophageal cancer and N-acetylation polymorphism. METHODS: To analyze the distribution of N-acetyltransferase 2 polymorphism in Japanese patients with esophageal squamous cell cancer, a molecular genotyping method using a polymerase chain reaction-based restriction fragment length polymorphism was used. RESULTS: Based on an analysis of 71 Japanese patients with esophageal squamous cell cancer and 329 healthy control subjects, the distribution of the slow acetylator phenotype was significantly higher in esophageal cancer patients than in the controls (19.7% and 9.4%, respectively, p = 0.040). The odds ratio of esophageal cancer for the slow phenotype was 2.55 (95% CI = 1.15-5.65, p = 0.023) compared with the rapid type. Furthermore, a significant difference between the distribution of acetylator phenotype and the incidence of lymph node metastasis and lymphatic involvement was found based on the clinicopathological features of these cancers. Esophageal cancer patients with a higher smoking exposure history tended to have the rapid acetylator phenotype. CONCLUSION: These results suggest that N-acetylation polymorphism may be implicated as a genetic trait affecting an individual's susceptibility and biological behavior of esophageal squamous cell cancer.

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.

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.