Targeting the CXCR4/CXCL12 axis in treating epithelial ovarian cancer.

Ovarian carcinoma is the most crucial and difficult target for available therapeutic treatments among gynecological malignancies, and great efforts are required to find an effective solution. Molecular studies showed that the chemokine stromal cell-derived factor-1 (also known as CXCL12) and its receptor, CXCR4, are key determinants of tumor initiation, progression and metastasis in ovarian carcinomas. Hence, it is generally believed that blocking the CXCR4/CXCL12 pathway could serve as a potential therapy for patients with ovarian cancer. Herein, we investigated the role of the CXCR4/CXCL12 axis in regulating ovarian cancer progression. Using flow cytometry, a real-time PCR and western blot analyses, we showed that the chemokine receptor CXCR4 protein and mRNA were overexpressed in human epithelial ovarian cancer cell lines, and these were closely correlated with poor outcomes. Moreover, silencing CXCR4 by small hairpin RNA in HTB75 cells reduced cell proliferation, migration and invasion and significantly reduced RhoA and Rac-1/Cdc42 expressions, whereas overexpression of CXCR4 in SKOV3 cells significantly increased cell migration and markedly increased RhoA, Rac-1/Cdc42 levels. Silencing CXCR4 also led to decreased in vitro cytotoxicity of AMD3100, a specific antagonist of CXCR4, which exerts its effect upon CXCR4 expression. Remarkably, knockdown of CXCR4 in HTB75 cells led to a significantly decreased capability to form tumors in vivo, and the Ki67 proliferation index of xenograft tumors showed a dramatic reduction. Our results revealed that the CXCR4/CXCL12 pathway represents a promising therapeutic target for epithelial ovarian carcinoma.

Congenital interstitial cell of cajal hyperplasia with neuronal intestinal dysplasia.

Interstitial cells of Cajal (ICCs) are intestinal pacemaker cells that initiate peristalsis in the stomach and intestine, and are considered to be precursors of gastrointestinal stromal tumors (GISTs). We report a 2-year-old girl who suffered from scanty stool passage since birth. On barium enema, the distal colon was rigid with narrow lumen, whereas the proximal colon was dilated and atonic. She received right hemicolectomy and ileostomy. Histopathologically, there was continuous proliferation of spindle cells located between the layers of the muscularis propria throughout the right colon. These spindle cells were positive for c-kit and CD34 but negative for myogenic or neurogenic markers, indicating they are ICCs. No germline or somatic mutation of the juxtamembrane domain of c-kit gene was detected. In addition, the changes of the submucosal plexus fulfilled the histologic criteria of neuronal intestinal dysplasia type B. To our knowledge, this is the first reported case of congenital ICC hyperplasia. Further studies of ICC development may contribute to better understanding of the pathogenesis of this congenital malformation and the tumorigenesis of GIST.

Somatic mutations of beta-catenin play a crucial role in the tumorigenesis of sporadic hepatoblastoma.

Hepatoblastoma (HB) is the most common malignant hepatic tumor during early childhood. Its molecular pathogenesis is still poorly understood. Mutations of adenomatous polyposis coli (APC) gene have been identified in sporadic cases and in individuals associated with familial adenomatous polyposis syndrome. beta-catenin is a key element in the cadherin-mediated cell adhesion system and Wnt/wingless pathway, and is controlled by APC. APC affects the degradation of beta-catenin by its NH(2)-terminal phosphorylation on the serine/threonine residues of exon 3. Mutations of these phosphorylation sites are primary targets for activating mutations in several types of human cancer and lead to nuclear accumulation of beta-catenin protein. In this study, we examined nine patients with HB using immunohistochemistry and direct DNA sequencing. All nine cases showed predominant nuclear expression of beta-catenin. Eight cases (89%) showed mutations involving exon 3 of the beta-catenin gene, including five with deletions and three with missense mutations. All five deletions were in-frame deletions without frameshift. The very high frequency of mutations in the beta-catenin gene suggests that beta-catenin mutations are crucial in the tumorigenesis of HB.

Well-differentiated fetal adenocarcinoma of the lung.

We describe the case of a 43-year-old woman with a tumor shadow in the upper lobe of the left lung. The tumor was initially suspected to be a carcinoid tumor, following percutaneous needle biopsy. Subsequently, a left upper lobectomy was performed, and a well-differentiated fetal adenocarcinoma was diagnosed histologically. Unlike the biphasic epithelial and stromal features of pulmonary blastoma, it was composed solely of malignant glands of embryonal appearance.

Benign recurrent intrahepatic cholestasis.

Benign recurrent intrahepatic cholestasis is a rare disorder of unknown etiology and has not yet been reported in Taiwan. We report a case with a typical clinical course. A 17-year-old Taiwanese boy had three episodes of pruritus and jaundice from February 1993 to July 1995, each lasting 3 to 4 months. Jaundice spontaneously subsided and he was symptom-free during periods of remission. A fourth episode of pruritus began in July 1995, with jaundice developing later and lasting for 3 months. Laboratory tests revealed direct hyperbilirubinemia. Endoscopic retrograde cholangiopancreatography showed normal intra- and extrahepatic biliary trees. Light microscopy of a liver biopsy sample revealed hepatocellular and canalicular cholestasis with bile retention in the Kupffer cells. Benign recurrent intrahepatic cholestasis was diagnosed after exclusion of other possible causes of jaundice. The patient made an uneventful recovery.

Frequent nuclear expression of beta-catenin protein but rare beta-catenin mutation in pulmonary sclerosing haemangioma.

BACKGROUND: Pulmonary sclerosing haemangioma (PSH) is an uncommon tumour that is composed of glandular/papillary lining cells and polygonal cells. The biological behaviour of this tumour has been investigated; however, the molecular pathogenesis of PSH remains unknown. AIMS: To characterise the role of the Wnt/beta-catenin pathway in the genesis of PSH. METHODS: 37 PSH samples were investigated immunohistochemically for detection of the beta-catenin protein and direct sequencing of exon 3 of the beta-catenin gene. RESULTS: Nuclear expression of beta-catenin was found in the lining component of 23 tumours (62%) and in the polygonal component of 11 tumours (30%). The expression of beta-catenin was stronger in the lining component, but weaker in the polygonal component. Interestingly, all the tumours with expression of beta-catenin in the polygonal component also expressed beta-catenin in the lining component. However, mutation of exon 3 of the beta-catenin gene was detected in only one tumour that expressed nuclear beta-catenin in lining and polygonal components. CONCLUSIONS: The Wnt/beta-catenin pathway is involved in the genesis of PSH, but mutation of exon 3 of the beta-catenin gene rarely contributes to the activation of the Wnt/beta-catenin pathway in PSH.

Adenomyosis in the broad ligament and tamoxifen: report of a case.

Adenomyosis confined to the broad ligament is extremely rare. Herein we present a case of adenomyosis in the broad ligament with unusual gross features. This 41-year-old woman had been on tamoxifen therapy for 3 years due to breast cancer. Ten months after discontinuing tamoxifen, she underwent exploratory laparotomy for a right adnexal mass suspected as ovarian malignancy. At laparotomy, the mass was located in the right broad ligament with a fibrous stalk connecting to the uterus. Total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed. Histopathologic examination revealed adenomyosis with cyst formation and an unusual thick capsule. The possible effects of tamoxifen upon the uterus are discussed in this article, in view of reports of tamoxifen associated with endometrial carcinoma and endometriosis.

Expression of mutant nuclear beta-catenin correlates with non-invasive hepatocellular carcinoma, absence of portal vein spread, and good prognosis.

beta-catenin has functions both in the cadherin-mediated cell adhesion system and in the signalling pathway that mediates dorsal axis patterning in the embryo; it has been shown to be aberrantly expressed or mutated in diverse types of human tumour, but the biological significance of this remains to be clarified. To elucidate the clinical implications of aberrant beta-catenin expression and the potential differences between mutant and wild-type beta-catenin protein expression in hepatocellular carcinoma (HCC), the protein expression was analysed by immunohistochemical staining, supplemented by the analysis of gene mutation. Among 372 unifocal primary HCCs, beta-catenin was detected in the tumour cell membrane alone in 272 tumours (group A) and also in the nuclei in 100 (group B). In group A, 148 tumours had decreased beta-catenin expression, but the reduction did not correlate with invasion or prognosis. When compared with group A, however, group B had significantly lower frequencies of hepatitis B surface antigen carrier (p=0.015), and alpha-fetoprotein elevation (p=0.0003), but more often had non-invasive HCC (p<0.001) and better survival (p=0.01). Nuclear beta-catenin expression strongly correlated with mutation of the gene (p<0.00001). In group B, HCC with mutant nuclear beta-catenin correlated positively with non-invasive (stage 1) tumour and inversely with portal vein tumour thrombi (stage 3 HCC), and had significantly better 5-year survival, p<0.001 and p<0.0003, respectively. These results suggest that beta-catenin mutation plays an important role in the tumourigenesis of a subset of HCC of good prognosis, and that mutant and wild-type nuclear beta-catenin proteins are not functionally equivalent.

Differentiation of ovarian mucinous carcinoma and metastatic colorectal adenocarcinoma by immunostaining with beta-catenin.

AIMS: To investigate whether localization of beta-catenin is helpful in differentiating primary ovarian mucinous carcinoma and colorectal adenocarcinoma metastatic to the ovary. Extra-ovarian cancers which metastasize to the ovaries, especially from colorectal adenocarcinoma, frequently mimic primary ovarian carcinomas, particularly endometrioid and mucinous types. Distinguishing primary ovarian carcinoma from metastatic colorectal carcinoma is important for both therapeutic and prognostic reasons. Even after thorough histological examination, metastatic colorectal adenocarcinomas are still often mistaken for primary ovarian adenocarcinomas. Although some tumour makers have been advocated and are helpful in most cases, sometimes the distinction between primary mucinous carcinoma and metastatic colorectal carcinoma remains a problem. Activation of Wnt signalling through mutations of APC or beta-catenin is a key event in the development of colorectal cancer. These mutations lead to nuclear localization of beta-catenin, which can be demonstrated immunohistochemically. METHODS AND RESULTS: Formalin-fixed paraffin-embedded specimens from 43 primary ovarian mucinous carcinomas and 23 metastatic colorectal adenocarcinomas were included in this study. Sections were immunostained with antibodies to beta-catenin, cytokeratin (CK)7, CK20 and carcinoembryonic antigen (CEA). Nuclear localization of beta-catenin was found in 83% (19/23) of metastatic colorectal cancers and 9% (4/43) of ovarian mucinous carcinomas. Ovarian mucinous carcinomas were usually positive for CK7 (34/43, 79%). For comparison, 40 non-mucinous carcinomas of the ovary and 42 metastatic adenocarcinomas from other organs were also immunostained with antibodies against beta-catenin. Although nuclear localization of beta-catenin was occasionally seen in non-mucinous carcinoma of the ovary and metastatic adenocarcinoma from other organs, such tumours were usually distinguishable by their clinicopathological picture and rarely raised diagnostic problems. CONCLUSIONS: Immunostaining of beta-catenin is a useful marker for differentiating between ovarian mucinous carcinoma and metastatic colorectal adenocarcinoma.

Beta-catenin mutations are associated with a subset of low-stage hepatocellular carcinoma negative for hepatitis B virus and with favorable prognosis.

To better understand the role of beta-catenin mutation in hepatocellular carcinoma (HCC), we correlated the gene mutation with hepatitis virus B (HBV) and hepatitis virus C (HCV) status and the clinicopathological features in 366 patients with resected primary unifocal HCC. beta-Catenin mutations were also analyzed in 55 patients with multifocal HCC (68 tumors). Of the whole series, 57 (13.1%) of 434 tumors examined had beta-catenin mutations, 34 occurred at the serine/threonine residues of the GSK-3beta region of beta-catenin. Outside the GSK-3beta phosphorylation site, codons 32 and 34 were two mutational hot spots (17 tumors). The non-HBV-related HCC that was predominantly HCV related had a higher frequency of mutation (P: < 0.00001) and more frequent mutations at codon 45 than HBV-related HCC. HBV-related HCC had a younger mean age (P: < 0.00001), and higher male-to-female ratio (P: < 0.003) and positive familial history of HCC (P: < 0.014). Among 366 unifocal HCCs selected for clinicopathological analysis, beta-catenin mutations were associated with grade I (P: = 0.005) and stage I and II HCC (P: < 0.0001), and a better 5-year survival rate (P: = 0. 00003). These findings suggest mechanisms for beta-catenin mutations differ between HBV-related and non-HBV-related HCCs, and that beta-catenin mutation is a favorable prognostic factor related to low stage. beta-Catenin mutation was associated with nuclear expression of the protein (P: < 0.00001), but we failed to detect point or large fragment deletion mutation in 39 HCCs with nuclear beta-catenin expression, presumably wild-type protein. HCCs expressing mutant nuclear beta-catenin had a better 5-year survival rate (P: < 0.007), suggesting that mutant and wild-type nuclear beta-catenin proteins are not functionally equivalent and deserve more studies for further clarification.