EMMPRIN (extracellular matrix metalloproteinase inducer) is a novel marker of poor outcome in serous ovarian carcinoma

EMMPRIN is a member of the immunoglobulin superfamily of adhesion molecules and has a role in the activation of several matrix metalloproteinases (MMP). The objective of this study was to investigate the expression of EMMPRIN in effusions, primary and metastatic tumors of serous ovarian carcinoma patients, as well as to evaluate its association with clinicopathologic parameters and with MMP and integrin expression. Eighty effusions and eighty-three solid lesions were evaluated for expression of EMMPRIN mRNA using in situ hybridization (ISH). Protein expression was studied in 75 effusions and 55 biopsies using immunohistochemistry (IHC). EMMPRIN mRNA and protein were detected in carcinoma cells in 63/80 (79%) and 64/75 (85%) effusions, respectively. Expression was similar in peritoneal and pleural effusions. EMMPRIN was co-expressed with MMP-1 (P<0.001), MMP-9 (P=0.006) and the αv (P=0.013) and β1 (P=0.029) integrin subunits. In solid lesions, EMMPRIN localized most often to tumor cells (51/83 using ISH, 51/55 using IHC), but was also expressed in stromal and endothelial cells in approximately one third of the cases. EMMPRIN mRNA expression in tumor cells was most frequent in peritoneal metastases (P=0.03). EMMPRIN expression in carcinoma cells of solid tumors showed an association with that of MMP-9 (P=0.018), while labeling of stromal cells showed co-localization with the β1 integrin subunit (P=0.043). In survival analysis, EMMPRIN protein expression in stromal cells of primary tumors (P=0.012) and in endothelial cells of all solid tumors (P=0.023) correlated with poor survival. In conclusion, EMMPRIN is a novel prognostic marker in ovarian carcinoma, and is co-expressed with other metastasis-associated molecules in this malignancy. The identical phenotype of carcinoma cells in pleural and peritoneal effusions provides further evidence to our theory that cells at these sites share similar genotypic and phenotypic profiles. This revised version was published online in July 2006 with corrections to the Cover Date.     

Increased expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and MMP10, MMP23 in inflammatory bowel disease: Cross‐sectional study

It has been reported that EMMPRIN is involved in the regulation of immune response and the induction of MMPs production by fibroblasts. The aim of this study was to describe the intestinal gene expression and protein production of EMMPRIN, MMP23 and MMP10 in patients with ulcerative colitis (UC) and Crohn’s disease (CD) and compared them with a control group. Gene expression of EMMPRIN, MMP10 and MMP23B was measured by RT‐PCR. In order to determine EMMPRIN and MMP protein expression, colonic tissues were immunostained. The results of the study showed EMMPRIN gene expression was upregulated in rectal mucosa from active (a)UC versus aCD patients (P = .045), remission (r)CD group (P = .0009) and controls (P < .0001). We detected differences between rUC and aCD (P = .004), rCD (P < .0001) or control group (P < .0001). EMMPRIN showed a higher expression in mucosa (intraepithelial lymphocytes), submucosa and adventitia (endothelial cells) from aCD patients. MMP23 levels were increased in aUC and aCD compared to rUC and rCD and the control group (P = .0001). EMMPRIN+/MMP23+─expressing cells were localized mainly in mucosa, muscular and adventitia from active UC patients. MMP10 gene expression was increased in aUC versus CD patients and the control group (P = .0001). MMP10 gene expression is associated with inflammation in UC patients (P = .0001, r² = .585). EMMPRIN+/MMP10+─producing cells were found mainly in all intestinal layers and perivascular inflammatory infiltrates from aUC patients. In conclusion, EMMPRIN, MMP23 and MMP10 were upregulated in patients with active UC versus remission UC , CD and control groups suggesting that, they are involved in the inflammatory process.     

Cytokines regulate matrix metalloproteinases in human uterine endometrial fibroblast cells through a mechanism that does not involve increases in extracellular matrix metalloproteinase inducer

PROBLEM: Endometriosis is the presence of ectopic uterine endometrial tissue in the peritoneal cavity. Peritoneal fluid samples of women with endometriosis show elevated interleukin-1 (IL-1)beta, tumor necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta(1) levels, indicating that an altered immune system may play an important role in the pathogenesis of endometriosis. The invasion of ectopic endometrium into peritoneal mesothelium requires matrix metalloproteinases (MMPs) for tissue remodeling. Several MMPs are differentially expressed in human uterine endometrium with menstrual endometrium showing the highest level of expression. MMPs are stimulated by cytokines and also by the protein Extracellular Matrix Metalloproteinase Inducer (EMMPRIN). METHOD OF STUDY: To determine the role of cytokines in ectopic endometrial invasion, we investigated whether cytokines could regulate MMP production by endometrial fibroblast cells and whether this stimulation occurred through an effect on EMMPRIN expression. Human uterine fibroblasts (HUF) were treated with IL-1beta, TGF-beta(1) and TNF-alpha in a dose dependent and time dependent manner (C, 0.1, 1, 10 ng/mL IL-1beta or TGF-beta(1); C, 2, 10, 50 ng/mL TNF-alpha) for 0, 6, 12, and 24 hr. Cell conditioned medium samples were collected and concentrated at each timepoint for immunoblot analysis. Cellular RNA was collected for real time PCR analysis of MMPs-1, -2, -3 and EMMPRIN mRNA levels. RESULTS: Our results showed that IL-1beta stimulated MMP-1 protein secretion and mRNA levels in a time dependent manner (P < 0.05), MMP-2 mRNA in a time dependent manner and MMP-3 in a time and dose dependent manner. TNF-alpha stimulated MMP-1 and -3 protein secretion in a time dependent manner and stimulated MMP-1, -2 and -3 mRNA levels in a time dependent manner (P < 0.05). Neither IL-1beta nor TNF-alpha treatment affected MMP-2 protein secretion. TGF-beta(1) inhibited MMP-1 and MMP-2 mRNAs at the highest treatment dose after 24 hr but there was no effect on protein secretion. TGF-beta(1) exerted no effect on MMP-3 mRNA or protein secretion (P < 0.05). Neither of the cytokines affected EMMPRIN protein or mRNA levels but the 10 ng/mL TGF-beta(1) treatment did cause a reduction in EMMPRIN mRNA levels. CONCLUSIONS: These data show that elevated cytokines may play a role in the establishment of ectopic endometrium in the peritoneal cavity by stimulating MMPs to remodel the mesothelial lining of the peritoneum thus allowing for tissue invasion. The stimulation of MMPs by cytokines occurred without any change in EMMPRIN expression whereas the inhibitory effect of TGF-beta(1) involved a reduction in EMMPRIN mRNA levels.     

PPARs配体对巨噬细胞、泡沫细胞细胞外基质金属蛋白酶诱导因子表达的影响

目的：观察PPAR α、γ配体对巨噬细胞、泡沫细胞细胞外基质金属蛋白酶诱导因子(EMMPRIN)表达的影响。方法：体外诱导THP-1单核细胞转化为巨噬细胞、泡沫细胞，分别加入PPAR α配体氯贝特（clofibrate）、PPARγ配体吡格列酮(pioglitazone)共同培养，应用Real-time RT-PCR和Western blotting测定巨噬细胞、泡沫细胞中EMMPRIN基因和蛋白表达，ELISA测定细胞培养上清液MMP-9浓度，Zymgraphy法测定MMP-9活性。结果：氯贝特和吡格列酮均能显著抑制巨噬细胞和泡沫细胞EMMPRIN的表达，此抑制作用与PPAR α、γ配体抑制MMP-9分泌及活性的趋势一致。结论：PPAR α、γ配体均可抑制巨噬细胞、泡沫细胞EMMPRIN的表达，下调EMMPRIN可能是PPARs配体抑制粥样斑块局部MMPs产生的机制之一。     

Possible pathophysiological roles of mitogen-activated protein kinases (MAPKs) in endometriosis

PROBLEM: Endometriosis accompanies local inflammatory reactions in the peritoneal cavity. We examined the phosphorylation of mitogen-activated protein kinases (MAPKs), i.e. extracellular signal-regulated kinase (ERK), p38 MAPK (p38) and c-Jun N-terminal kinase (JNK) in endometriotic stromal cells, and their possible pathophysiological roles in endometriosis in relation to proinflammatory substances. METHOD OF STUDY: Endometriotic stromal cells were isolated from endometriomas and were cultured for the experiments. Phosphorylation of MAPKs in endometriotic stromal cells treated with interleukin (IL)-1beta, tumor necrosis factor (TNF)alpha and H(2)O(2) were examined by Western blot analysis. Effects of PD98059, SB202190 and SP600125 (inhibitors of ERK, p38 and JNK, respectively) on IL-1beta-induced secretion of IL-6 and IL-8, and on IL-1beta-induced expression of cyclo-oxygenase-2 (COX-2) in endometriotic cells were studied. In addition, eutopic endometrial tissues were collected, and the phosphorylation rate of p38 in eutopic endometrial tissues and endometriotic tissues were determined. RESULTS: IL-1beta, TNFalpha and H(2)O(2) stimulated the phosphorylation of ERK, p38 and JNK, while the total amounts of proteins of the respective MAPKs were virtually the same compared with those in the unstimulated controls. Both SB202190 and SP600125 suppressed IL-1beta-induced secretion of IL-6 and IL-8, and PD98059 suppressed IL-1beta-induced secretion of IL-8. Both SB202190 and PD98059 suppressed IL-1beta-induced expression of COX-2 in endometriotic cells. The p38 phosphorylation rates in the endometriotic tissues were significantly higher than those in the eutopic endometrial tissues of the same patients. CONCLUSIONS: Given the current theory that inflammatory changes are involved in the progression of endometriosis, MAPKs could play as pivotal intracellular signal transducers in endometriotic cells, and thus have a pathophysiological role in the disease.     

Tension Force Downregulates Matrix Metalloproteinase Expression and Upregulates the Expression of Their Inhibitors through MAPK Signaling Pathways in MC3T3-E1 cells

Objective: Matrix metalloproteinases (MMPs), produced by osteoblasts, catalyze the turnover of extracellular matrix (ECM) molecules in osteoid, and the regulation of MMP activity depends on interactions between MMPs and tissue inhibitors of metalloproteinases (TIMPs). We focused on the degradation process of ECM in osteoid that was exposed to mechanical strain, and conducted an in vitro study using MC3T3-E1 osteoblastic cells to examine the effects of tension force (TF) on the expression of MMPs and TIMPs, and activation of mitogen-activated protein kinase (MAPK) pathways.Design: Cells were incubated on flexible-bottomed culture plates and stimulated with or without cyclic TF for 24 hours. The expression of MMPs and TIMPs was examined at mRNA and protein levels by real-time RT-PCR and Western blotting, respectively. The phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, p38 MAPK, and stress-activated protein kinases/c-jun N-terminal kinases (SAPK/JNK) were examined by Western blotting.Results: TF decreased the expression of MMP-1, -3, -13 and phosphorylated ERK1/2. In contrast, TF increased the expression of TIMP-2, -3 and phosphorylated SAPK/JNK. The expression of MMP-2, -14, TIMP-1, -4 and phosphorylated p38 MAPK was unaffected by TF. MMP-1, -3 and -13 expression decreased in cells treated with the ERK inhibitor PD98059 compared with untreated control cells. The JNK inhibitor SP600125 inhibited the TF-induced upregulation of TIMP-2 and -3.Conclusions: The results suggest that TF suppresses the degradation process that occurs during ECM turnover in osteoid via decreased production of MMP-1, -3 and -13, and increased production of TIMP-2 and -3 through the MAPK signaling pathways in osteoblasts.     

Advances in serous tubal intraepithelial carcinoma: correlation with high grade serous carcinoma and ovarian carcinogenesis

Early serous carcinoma in fallopian tube or serous tubal intraepithelial carcinoma (STIC), an early lesion limited to the epithelium of the fallopian tube and firstly identified from specimen obtained by prophylactic salpingo-oophorectomy, has provided insight into pelvic high grade serous carcinoma (HGSC). Increasing evidence indicates that STIC is a likely precursor for HGSC and several studies have focused on this lesion and its clinical significance. This review addresses recent advances in recognizing STIC and its correlation with HGSC and ovarian carcinogenesis. It also describes evidence regarding the fallopian tube as a source of some HGSCs, the protocol for optimizing histological evaluation of the tubes, the spectrum of tubal lesions from benign to noninvasive carcinoma, changes in diagnostic criteria from purely morphologic characteristics to a combination of morphologic features and molecular biomarkers, and new studies about potential biomarkers. However, the direct evidence regarding STIC as the precursor of HGSC is still tantalizing due to other possibilities that may also explain the origin of pelvic HGSC. Further molecular genetic studies are required to address this important question.     

Suppressive effect of leflunomide metabolite (A77 1726) on metalloproteinase production in IL-1beta stimulated rheumatoid synovial fibroblasts

Leflunomide, an isoxazol derivative structurally unrelated to other immunomodulatory drugs, has proven to be efficacious in the treatment of rheumatoid arthritis (RA). This study was conducted to elucidate the mechanism by which leflunomide mediated antirheumatic effects. We investigated the effects of A77 1726, leflunomide's active metabolite, on mitogen-activated protein kinase (MAPK) activation in IL-1beta-stimulated rheumatoid synovial fibroblasts. The effects of A77 1726 on the secretion of matrix metalloproteinases (MMPs) from rheumatoid synovial fibroblasts were also examined. A77 1726 partially suppressed IL-1beta-induced ERK1/2 and p38 kinase activation. In contrast, A77 1726 efficiently suppressed IL-1beta-stimulated JNK1/2 kinase activation. Although no suppressive effect was demonstrated on MMP-2, A77 1726 markedly inhibited MMP-1, 3, and 13 secretions from IL-1beta-stimulated rheumatoid synovial fibroblasts. Tissue inhibitor of metalloproteinases-1 (TIMP-1) was constitutively produced from rheumatoid synovial fibroblasts and the suppressive effects of A77 1726 on TIMP-1 production were minimal. Our results suggest that the suppression of the MAPK signalling pathway and MMP synthesis in rheumatoid synovial fibroblasts is a possible mechanism for the inhibitory activity of leflunomide against rheumatoid arthritis.     

Adenomatous polyposis coli (APC) protein expression in primary and metastatic serous ovarian carcinoma

The aim of this study was to investigate protein expression of adenomatous polyposis coli (APC) in primary and metastatic serous ovarian carcinoma. The expression of beta-catenin and E-cadherin was additionally analyzed. One hundred and thirteen primary (n = 56) and metastatic (n = 57) lesions were immunohistochemically stained for APC, E-cadherin, and beta-catenin. Staining extent was scored. Possible differences in immunoreactivity in primary and metastatic sites and the association between the proteins analyzed were evaluated statistically. Cytoplasmic immunoreactivity for APC was found in 67/113 (59%) tumors, most often in the majority (> 50%) of cells. E-cadherin was detected in 102/113 (90%) carcinomas, while beta-catenin was expressed in 109/113 (97%) specimens. Nuclear expression of beta-catenin was seen in 3/113 (3%) specimens, all negative for APC. APC and beta-catenin were often coexpressed, but this finding failed to reach statistical significance (p = 0.11). A significant association was seen between E-cadherin and beta-catenin expression (p = 0.001). APC expression was comparable in primary and metastatic tumors (p > 0.05). In conclusion, APC expression is absent in a considerable number of both primary and metastatic ovarian carcinomas, but this finding is only rarely coupled to nuclear accumulation of beta-catenin. These findings support the role for beta-catenin signaling via the Wingless/Wnt pathway in ovarian carcinoma. The mechanism behind the down-regulated expression of APC in serous ovarian carcinoma and its significance has yet to be elucidated.     

细胞外基质金属蛋白酶诱导因子和内皮素转化酶对非小细胞肺癌患者术后淋巴结转移和预后的影响

目的： 研究细胞外基质金属蛋白酶诱导因子(EMMPRIN)和内皮素转化酶(ECE)在非小细胞肺癌（NSCLC）组织中表达的临床意义。 方法： 用免疫组织化学方法检测77例NSCLC组织中EMMPRIN和ECE的表达情况，分析其与肿瘤大小、癌的组织学类型、组织分化程度、淋巴结转移和预后的关系。 结果： 77例NSCLC组织中EMMPRIN和ECE的阳性表达率分别为66%和45%。EMMPRIN和ECE的表达均与淋巴结转移呈正相关（均P＜0.01，r=0.371和0.467），两者表达阳性组术后生存期均明显短于阴性组（均P＜0.01）。NSCLC组织中EMMPRIN和ECE的表达之间呈正相关（P＜0.05，r=0.243）。EMMPRIN和ECE的表达与肿瘤大小、癌组织学类型和组织分化程度均无相关性（P>0.05）。 结论： EMMPRIN和ECE的表达与NSCLC的淋巴结转移和预后密切相关，它们的高表达提示非小细胞肺癌患者预后不良。     

Differential expression of extracellular matrix metalloproteinase inducer (CD147) in normal and ulcerated corneas: role in epithelio-stromal interactions and matrix metalloproteinase induction

Extracellular matrix metalloproteinase inducer (EMMPRIN) was originally identified on the tumor cell surface as an inducer of matrix metalloproteinase (MMP) production in neighboring fibroblasts. Here we demonstrate a role for EMMPRIN in MMP induction during corneal wound healing. MMP and EMMPRIN expression was analyzed in normal and ulcerated human corneas, as well as in corneal epithelial and stromal cells in culture using confocal microscopy, zymography, immunoblots, and real-time polymerase chain reaction. In normal cornea EMMPRIN was predominantly expressed in the epithelium but was markedly induced in the anterior stroma of ulcerated corneas. This coincided with MMP-2 induction that co-localized with EMMPRIN at the epithelio-stromal boundary. The role of epithelial-stromal interaction in MMP induction was investigated in an in vitro co-culture system and demonstrated an induction and co-localization of EMMPRIN and MMP-2 in the fibroblasts at the interface with epithelial cells. Direct contact of fibroblasts with EMMPRIN-containing purified epithelial cell membranes also induced MMP-1, MMP-2, and EMMPRIN and this was inhibited by a blocking anti-EMMPRIN antibody, suggesting that EMMPRIN was primarily responsible for this induction. These findings, and the up-regulation of EMMPRIN by epidermal growth factor and transforming growth factor-beta, demonstrate a role for EMMPRIN in wound healing and suggest that sustained local up-regulation of EMMPRIN and MMPs in chronic situations in which healing is delayed may lead to excessive matrix degradation and corneal melts.     

非小细胞肺癌中EMMPRIN和HGF的表达及其对淋巴结转移和预后的影响

目的： 研究细胞外基质蛋白酶诱导因子(EMMPRIN)和肝细胞生长因子(HGF)在非小细胞肺癌（NSCLC）组织中的表达及其临床意义。方法： 免疫组织化学方法检测77例NSCLC组织中EMMPRIN与HGF的表达，分析其与患者吸烟情况、肿瘤大小、组织学类型、组织分化程度、淋巴结转移和预后的关系。 结果：77例NSCLC组织中EMMPRIN与HGF的阳性表达率分别为68%和44%。EMMPRIN与HGF的表达均与淋巴结转移呈正相关（r=0.371和0.339，P＜0.01），与患者术后生存时间呈负相关（P＜0.01）。EMMPRIN与HGF的表达均与患者吸烟、肿瘤大小、组织学类型和组织分化程度无关（P＞0.05）。EMMPRIN与HGF的表达之间呈正相关（r=0.281,P＜0.01）。结论: EMMPRIN和HGF的表达与NSCLC的淋巴结转移和预后密切相关，它们的高表达提示NSCLC患者预后不良。     

Differential expression of matrix metalloproteinase (MMP)-2, MMP-9 and tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 in non-melanoma skin cancer: implications for tumour progression

AIMS: To investigate the expression of matrix metalloproteinase (MMP)-2, MMP-9, and tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 in non-melanoma skin cancer (NMSC) and to compare their expression between different tumour types and with clinicopathological factors. METHODS AND RESULTS: A study of 11 normal skin, 29 Bowen's disease (BD), 40 squamous cell carcinoma (SCC) and 38 basal cell carcinoma (BCC) samples for MMP-2, MMP-9, TIMP-1 and TIMP-2 expression was carried out using immunohistochemistry and in situ hybridization. The expression of all metalloproteinases was greater in tumours than in normal skin. MMP-2 and MMP-9 expression was more extensive in the stroma of SCC than of BCC or BD. TIMP-1 expression was greater in the stroma of BCC than of SCC or BD and TIMP-2 expression was greater in the stroma of SCC than of BD. There was a correlation between increased metalloproteinase expression and depth of lesion (MMP-2 and TIMP-2), inflammation (MMP-2, MMP-9, TIMP-1 and TIMP-2) and microvessel density (MMP-2, MMP-9 and TIMP-2). CONCLUSIONS: MMP-2, MMP-9, TIMP-1 and TIMP-2 play an important role in the pathogenesis of non-melanoma skin cancer, but differ significantly in their expression levels between the tumour types examined. The immunoexpression of these proteins may be useful indicators of cutaneous cancer invasion and progression.     

SIRT2在浆液性卵巢癌细胞系中的表达及其对增殖、迁移和侵袭的影响

目的:研究SIRT2在卵巢表层上皮(ovarian surface epithelium,OSE)及浆液性卵巢癌(serous ovarian carcinoma,SOC)细胞系中的表达情况并从细胞增殖、迁移和侵袭这3个方面探讨SIRT2对SOC恶性生物学行为的影响。方法:运用Western blot技术检测OSE和SOC细胞系中SIRT2蛋白的表达水平;设计靶向SIRT2的siRNA,构建SIRT2过表达载体,分别瞬时转染OSE细胞系HOSEpi C和SOC细胞系HO8910,平板克隆形成实验和CCK-8实验研究SIRT2对细胞生长的影响;细胞划痕实验考察SIRT2在SOC细胞迁移中的作用;Transwell实验研究SIRT2对SOC细胞侵袭能力的影响。结果:5株SOC细胞系中SIRT2的表达水平显著低于OSE细胞系。在HOSEpi C细胞中沉默SIRT2,细胞克隆形成数增多,细胞活力增强。相反,在HO8910细胞中过表达SIRT2,细胞克隆形成数减少,细胞活力降低。沉默SIRT2促进HOSEpi C细胞的迁移,而过表达SIRT2则抑制HO8910细胞的迁移。沉默SIRT2的HOSEpi C细胞侵袭能力明显增加,而过表达SIRT2的HO8910细胞侵袭能力则显著降低。结论:SIRT2在SOC细胞中表达显著下调。SIRT2在OSE细胞中是肿瘤抑制蛋白,抑制细胞增殖、迁移和侵袭。     

Mutational analysis of BRAF and KRAS in ovarian serous borderline (atypical proliferative) tumours and associated peritoneal implants

There is debate as to whether peritoneal implants associated with serous borderline tumours/atypical proliferative serous tumours (SBT/APSTs) of the ovary are derived from the primary ovarian tumour or arise independently in the peritoneum. We analysed 57 SBT/APSTs from 45 patients with advanced‐stage disease identified from a nation‐wide tumour registry in Denmark. Mutational analysis for hotspots in KRAS and BRAF was successful in 55 APSTs and demonstrated KRAS mutations in 34 (61.8%) and BRAF mutations in eight (14.5%). Mutational analysis was successful in 56 peritoneal implants and revealed KRAS mutations in 34 (60.7%) and BRAF mutations in seven (12.5%). Mutational analysis could not be performed in two primary tumours and in nine implants, either because DNA amplification failed or because there was insufficient tissue for mutational analysis. For these specimens we performed VE1 immunohistochemistry, which was shown to be a specific and sensitive surrogate marker for a V600E BRAF mutation. VE1 staining was positive in one of two APSTs and seven of nine implants. Thus, among 63 implants for which mutation status was known (either by direct mutational analysis or by VE1 immunohistochemistry), 34 (53.9%) had KRAS mutations and 14 (22%) had BRAF mutations, of which identical KRAS mutations were found in 34 (91%) of 37 SBT/APST–implant pairs and identical BRAF mutations in 14 (100%) of 14 SBT/APST–implant pairs. Wild‐type KRAS and BRAF (at the loci investigated) were found in 11 (100%) of 11 SBT/APST–implant pairs. Overall concordance of KRAS and BRAF mutations was 95% in 59 of 62 SBT/APST–implant (non‐invasive and invasive) pairs (p < 0.00001). This study provides cogent evidence that the vast majority of peritoneal implants, non‐invasive and invasive, harbour the identical KRAS or BRAF mutations that are present in the associated SBT/APST, supporting the view that peritoneal implants are derived from the primary ovarian tumour. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Localization of the human membrane-type 2 matrix metalloproteinase gene (MMP15) to 16q12.1 near DNA elements that are part of centromeric and non-centromeric heterochromatin of 11 human chromosomes

We have localized a second gene for membrane-type matrix metalloproteinases, MT2-MMP, to chromosome 16q12 by in situ hybridization. FISH experiments using a genomic PAC clone containing the MT2-MMP gene resulted in an unusual hybridization pattern detecting centromeric and non-centromeric heterochromatin regions or its flanking sequences in 11 human chromosomes in addition to the MT2-MMP locus on chromosome 16q12. The detailed analysis of this hybridization pattern using molecular cytogenetic methods together with the specific hybridization of the MT2-MMP cDNA allowed a refined mapping of the gene to 16q12.1, directly adjacent to the 16q heterochromatin. Our findings may give some insights into the evolution of the MMP gene family.     

KRAS (but not BRAF) mutations in ovarian serous borderline tumour are associated with recurrent low‐grade serous carcinoma

BRAF and KRAS mutations in ovarian serous borderline tumours (OSBTs) and ovarian low‐grade serous carcinomas (LGSCs) have been previously described. However, whether those OSBTs would progress to LGSCs or whether those LGSCs were developed from OSBT precursors in previous studies is unknown. Therefore, we assessed KRAS and BRAF mutations in tumour samples from 23 recurrent LGSC patients with a known initial diagnosis of OSBT. Paraffin blocks from both OSBT and LGSC samples were available for five patients, and either OSBTs or LGSCs were available for another 18 patients. Tumour cells from paraffin‐embedded tissues were dissected out for mutation analysis by conventional polymerase chain reaction (PCR) and Sanger sequencing. Tumours that appeared to have wild‐type KRAS by conventional PCR–Sanger sequencing were further analysed by full COLD (co‐amplification at lower denaturation temperature)‐PCR and deep sequencing. Full COLD‐PCR was able to enrich the amplification of mutated alleles. Deep sequencing was performed with the Ion Torrent personal genome machine (PGM). By conventional PCR–Sanger sequencing, BRAF mutation was detected only in one patient and KRAS mutations were detected in ten patients. Full COLD‐PCR deep sequencing detected low‐abundance KRAS mutations in eight additional patients. Three of the five patients with both OSBT and LGSC samples available had the same KRAS mutations detected in both OSBT and LGSC samples. The remaining two patients had only KRAS mutations detected in their LGSC samples. For patients with either OSBT or LGSC samples available, KRAS mutations were detected in seven OSBT samples and six LGSC samples. Surprisingly, patients with the KRAS G12V mutation have shorter survival times. In summary, KRAS mutations are very common in recurrent LGSC, while BRAF mutations are rare. The findings indicate that recurrent LGSC can arise from proliferation of OSBT tumour cells with or without detectable KRAS mutations. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

An immunohistochemical study of the extracellular matrix in oral squamous cell carcinoma and its association with invasive and metastatic potential

The expression of extracellular matrices (ECMs) laminin (LN), type IV collagen (IV C), heparansulphate proteoglycan (HS-PG), fibronectin (FN), tenascin (TN), decorin and vitronectin (VN) was examined immunohistochemically in 112 primary tumours and 29 metastatic cervical lymph nodes in oral squamous cell carcinoma (OSCC). In highly invasive primary tumours, the expression of LN, IV C and HS-PG in the basement membrane along the tumour-stroma borderline and the expression of decorin and VN in the tumour stroma at the invasive site were all significantly decreased. The expression of FN and TN in the tumour stroma at the same site was markedly increased. In peritumour stroma in metastatic lymph nodes, LN, IV C, HS-PG, decorin and VN were weakly expressed, while FN and TN were strongly expressed. Thus, the staining pattern of the ECMs in the metastatic lymph nodes was similar to that in highly invasive primary tumours. Furthermore, in primary tumours of metastatic cases, the expression of LN, IV C, HS-PG, decorin and VN obviously decreased, while the expression of FN and TN increased when compared with those of the non-metastatic cases. The investigation of ECMs in OSCC was valuable in predicting tumour behaviour.