Microscopic intraneural perineurial cell proliferations in patients with neurofibromatosis type 1

Benign peripheral nerve sheath tumors (PNSTs) showing more than one line of differentiation (hybrid PNSTs) have been increasingly recognized, mainly due to awareness of their existence and as a consequence of increased use of immunohistochemisty during the last decade. Two recent studies suggested overrepresentation of hybrid tumors among benign PNSTs in patients with neurofibromatosis type 1 (NF-1). This study was performed to assess the presence of perineurial cells in microscopic (early) neurofibromatous lesions and normal-looking peripheral nerves in specimens from 5 patients with NF-1 using markers of perineurial cell differentiation (epithelial membrane antigen, claudin-1, and glucose transporter 1). In 2 patients, multiple normal looking nerve fibers as well as hypertrophied nerves and microscopic tumor nodules showed variable intraneural perineurial cell proliferations that frequently occupied the whole nerve fascicle resulting in multiple microscopic reticular perineurioma-like nodules (microscopic hybrid neurofibromatosis/perineuriomatosis). None of the cases showed the onion skin pattern of intraneural perineurioma. However, other nerve fibers within the same specimens showed normal compact rim of perineurium without any detectable intraneural perineurial cells. Both patients had concurrent multiple larger PNSTs (plexiform neurofibromas, hybrid neurofibroma/perineurioma and lesions with features intermediate between the 2 types). One specimen harboring high-grade malignant PNST and 2 specimens with large solitary neurofibromas displayed no intraneural perineurial cells. These observations suggest that intraneural perineurial proliferations are part of the early lesions in the setting of constitutional NF-1 inactivation and support the concept of pure and hybrid perineuriomatous lesions as novel member of the spectrum of PNSTs in NF-1.     

Claudin-1 is expressed in perineurioma-like low-grade fibromyxoid sarcoma

Low-grade fibromyxoid sarcoma is a soft tissue sarcoma with recurrent and low metastatic potential, which has characteristic FUS-CREB3L2 or FUS-CREB3L1 fusions. Perineurioma is a peripheral nerve sheath neoplasm, which is usually benign. Low-grade fibromyxoid sarcoma and perineurioma can appear morphologically similar, particularly in small biopsy specimens, and distinction between the 2 entities is important for appropriate treatment. Low-grade fibromyxoid sarcoma is negative for most immunohistochemical markers, whereas perineuriomas stain variably for epithelial membrane antigen, CD34 and claudin-1, a tight-junction associated protein. We studied 15 cases of genetically proven low-grade fibromyxoid sarcoma that at least focally resembled perineurioma, with antibodies to claudin-1 and epithelial membrane antigen. Of these, 11 showed positivity for epithelial membrane antigen and all 15 were positive for claudin-1; in all cases, expression of claudin-1 was equal to or greater than the corresponding epithelial membrane antigen expression. This study emphasizes that claudin-1 is significantly expressed in low-grade fibromyxoid sarcomas. This has implications toward the accurate diagnosis of both tumors, and, as positivity for claudin-1 in low-grade fibromyxoid sarcoma is not previously documented, suggests that there might be underdiagnosis of low-grade fibromyxoid sarcoma. Although positivity for claudin-1 remains useful as an adjunct marker for perineurioma, it should be taken in context with clinical findings, morphology, and the additional immunoprofile.     

Meningial perineurioma: a benign peripheral nerve sheath tumor in a previously unrecognized central nervous system location, mimicking meningioma

Perineurioma is an uncommon, mostly benign, spindle-cell tumor of peripheral nerve sheath origin with a predilection for the soft tissues. Although increasing awareness points to the sites of involvement by perineurioma possibly being as ubiquitous as those frequented by schwannian tumors, only one intracerebral example has been described to date. We report on a surgically resected perineurioma of the falx cerebri in an 86-year-old woman. Preoperative imaging showed an enhancing extraaxial mass of 6 cm × 5.7 cm × 3.7 cm. Histologically, the tumor consisted of a proliferation of spindle cells interwoven by a lattice of basal lamina. Alongside a prevailing soft tissue perineurioma pattern, sclerosing and reticular areas were seen as well. Tumor cells coexpressed EMA and GLUT-1, and a minority immunoreacted for smooth muscle actin. Pericellular basal lamina was decorated with collagen type IV. No staining for S100 protein was detected. Mitotic activity was virtually absent, and the MIB1 labeling index averaged 2%. Ultrastructural examination revealed abundant pinocytotic vesicles within and conspicuous tight junctions between slender cytoplasmic processes which, in turn, were encased by discontinuous basal lamina. FISH analysis confirmed loss of at least part of one chromosome 22q. This observation calls attention to perineurioma as a novel item in the repertoire of low-grade meningial spindle cell neoplasms, in the differential diagnostic context of which it is apt to being misconstrued as either meningioma, solitary fibrous tumor, or neurofibroma. Confusion with the latter bears the risk of overgrading innocuous features of perineurioma as criteria for malignancy.     

Genetic alterations in quadruple malignancies of a patient with multiple sclerosis: their role in malignancy development and response to therapy

Multiple cancers represent 2.42% of all human cancers and are mainly double or triple cancers. Many possible causes of multiple malignancies have been reported such as genetic alterations, exposure to anti-cancer chemotherapy, radiotherapy, immunosuppressive therapy and reduced immunologic response. We report a female patient with multiple sclerosis and quadruple cancers of different embryological origin. Patient was diagnosed with stage III (T3, N1a, MO) medullary thyroid carcinoma (MTC), multicentric micropapillary thyroid carcinoma, scapular and lumbar melanomas (Clark II, Breslow II), and lobular invasive breast carcinoma (T1a, NO, MO). All tumors present in our patient except micropapillary thyroid carcinomas were investigated for gene alterations known to have a key role in cancer promotion and progression. Tumor samples were screened for the p16 alterations (loss of heterozygosity and homozygous deletions), loss of heterozygosity of PTEN, p53 alterations (mutational status and loss of heterozygosity) and mutational status of RET, HRAS and KRAS. Each type of tumor investigated had specific pattern of analyzed genetic alterations. The most prominent genetic changes were mutual alterations in PTEN and p53 tumor suppressors present in breast cancer and two melanomas. These co-alterations could be crucial for promoting development of multiple malignancies. Moreover the insertion in 4^th codon of HRAS gene was common for all tumor types investigated. It represents frameshift mutation introducing stop codon at position 5 which prevents synthesis of a full-length protein. Since the inactivated RAS enhances sensitivity to tamoxifen and radiotherapy this genetic alteration could be considered as a good prognostic factor for this patient.     

A neurogenic tumor containing a low-grade malignant peripheral nerve sheath tumor (MPNST) component with loss of p16 expression and homozygous deletion of CDKN2A/p16: a case report showing progression from a neurofibroma to a high-grade MPNST

Development of malignant peripheral nerve sheath tumors (MPNSTs) is a stepwise process that involves the alteration of many cell cycle regulators and the double inactivation of the NF1 gene. Inactivation of the TP53 gene and deletion of the CDKN2A/p16 gene are known to play an important role in the process. Herein, we present a 19-year-old man with a familial history of neurofibromatosis type 1, in whom the tumor arose from the intercostal nerve and showed 3 components: a neurofibroma, a low-grade MPNST, and a high-grade MPNST. Loss of p16 expression and homozygous deletion of the CDKN2A/p16 gene were observed in both the low-grade and the high-grade MPNST. In contrast to low-grade MPNSTs, high-grade MPNSTs generally tend to lose expression of p16 and harbor homozygous deletion of the CDKN2A/p16 gene. Loss of p16 expression and homozygous deletion of the CDKN2A/p16 gene in low-grade MPNST in our case might be related to its progression to high-grade MPNST. To the best of our knowledge, this is the first study correlating the p16 expression status and CDKN2A/p16 gene alteration in low-grade MPNSTs.     

TNFRp55 modulates IL-6 and nitric oxide responses following Yersinia lipopolysaccharide stimulation in peritoneal macrophages

While cytokines are major regulators of macrophage activation following host-pathogen interactions, they also act to limit inflammation to avoid tissue damage. In previous studies we reported the development of progressive Yersinia enterocolitica-induced reactive arthritis (ReA) in mice lacking the tumor necrosis factor receptor p55 (TNFRp55). In this work, we analyzed the response of TNFRp55^−/− macrophages to Y. enterocolitica antigens. We found higher concentration of nitric oxide (NO) in TNFRp55^−/− compared to wild-type macrophages in response to heat-killed Yersinia (HKY) and Yersinia outer membranes (OM). Moreover, Toll-like receptor (TLR)4 expression was increased in OM-stimulated TNFRp55^−/− versus wild-type (WT) macrophages. Accordingly, NO production was inhibited in TLR4-deficient macrophages following stimulation with OM, suggesting that LPS may function as a major OM component implicated in these responses. Thus, augmented NO production together with enhanced expression of inducible nitric oxide synthase (iNOS) and higher IL-6 production, may provide a pro-inflammatory setting in Yersinia LPS-stimulated TNFRp55^−/− macrophages. Augmented synthesis of NO and IL-6 was prevented by treatment with Polymyxin B, or by exposure to a specific NF-κB p65 oligonucleotide antisense, indicating the involvement of TLR4-mediated NF-κB activation in the unleashed pro-inflammatory response triggered by TNFRp55 deficiency. Thus, TNFRp55 modulates macrophage functions in response to Yersinia LPS stimulation through mechanisms involving NO, IL-6 and NF-κB pathways, suggesting an essential regulatory role of TNF via TNFRp55 signaling.     

Lactobacillus plantarum lipoteichoic acid down-regulated Shigella flexneri peptidoglycan-induced inflammation

Bacterial peptidoglycans (PGNs) are recognized by the host's innate immune system. This process is mediated by the NOD/CARD family of proteins, which induces inflammation by activating nuclear factor (NF)-κB. Excessive activation of monocytes by Shigella flexneri PGN (flexPGN) leads to serious inflammatory diseases such as intestinal bowel diseases (IBD) and Crohn's disease. In this study, we examined whether Lactobacillus plantarum lipoteichoic acid (pLTA) could attenuate the pro-inflammatory signaling induced by flexPGN in human monocytic THP-1 cells. Compared to control THP-1 cells, pLTA-tolerant cells showed a significant reduction in TNF-α and IL-1β production in response to flexPGN. We also examined the inhibition of NF-κB and the activation of mitogen-activated protein kinase (MAPK) in pLTA-tolerant cells. We found that the expression of NOD2 in pLTA-tolerant cells was down-regulated at the mRNA and protein levels, suggesting that pLTA is a potent modulator of the pro-inflammatory NOD2-related signaling pathways induced by flexPGN. Together, these data indicate that pLTA induces cross-tolerance against flexPGN. Notably, these effects are related not only to IL-1 signaling, which is known to play a role in LPS tolerance, but also to NOD-Rick signaling. This study provides insight into how commensal microflora may contribute to homeostasis of the host intestinal tract.     

Litopenaeus vannamei NF-κB is required for WSSV replication

Many viruses can hijack the host cell NF-κB as part of their life cycle, diverting NF-κB immune regulatory functions to favor their replications. There were several reports on the functions of Litopenaeus vannamei NF-κB (LvNF-κB) in White spot syndrome virus (WSSV) replication in vitro. Here, we studied the relationship between LvNF-κB family protein Dorsal (LvDorsal) and Relish (LvRelish) with WSSV replication in vivo. The expressions of LvDorsal and LvRelish were significantly upregulated by WSSV challenge. Virus loads and expression of viral envelope protein VP28 in LvDorsal or LvRelish silencing shrimps were significantly lower than the control shrimps injected with EGFP-dsRNA or PBS after challenge with 1 × 10⁵ copies WSSV/shrimp. In addition to the LvDorsal activation of WSV069 (ie1) and WSV303 promoter that we have reported, LvRelish can also activate WSV069 (ie1) and WSV303 promoter by dual luciferase reporter assays through screening 40 WSSV gene promoters that have putative multiple NF-κB binding sites. The promoter activity of the WSV069 (ie1) by LvDorsal activation was significantly higher than that by LvRelish activation. WSSV replication in LvDorsal, LvRelish or WSV303 silencing shrimps were significantly inhibited. These results indicate that the L. vannamei NF-κB family proteins LvDorsal and LvRelish expressions are significantly activated by WSSV challenge and WSSV replication partially relied on the activations of LvDorsal and LvRelish in vivo.     

Prognostic significance of HOXD13 expression in human breast cancer

Homeobox protein Hox-D13 has been recognized as a tumor suppressor in pancreatic cancer. To evaluate the function of HOXD13 in invasive breast cancer pathogenesis, we examined HOXD13 expression in 434 breast cancer tissues and 230 their counterpart normal breast tissues by immunohistochemistry using a tissue microarray (TMA). The association between HOXD13 expression and clinicopathological factors was analyzed by use of Chi-square test. Kaplan-Meier survival curves and log-rank tests were applied to analyze the survival status. Cox regression was applied for multivariate analysis of prognosis. We found that low HOXD13 expression accounts for 84.3% in breast cancer tissues. Low HOXD13 expression was significantly associated with large tumor size (P=0.038) and positive lymph node metastasis (LNM) (P=0.026). In Kaplan-Meier survival curves and log-rank tests, the patients with HOXD13-negative breast cancer showed significantly poorer outcomes (69.867 ± 1.058 months) in terms of overall survival (OS) than positive-HOXD13-expression patients (76.248 ± 1.069 months) (P=0.003). And in multivariate analysis, low level of HOXD13 expression was a significant unfavorable prognostic factor. So we conclude that down-regulation of HOXD13 might be a potentially useful prognostic marker for patients with breast cancer.     

CIAPIN1 gene silencing enhances chemosensitivity in a drug-resistant animal model in vivo

Overexpression of cytokine-induced apoptosis inhibitor 1 (CIAPIN1) contributes to multidrug resistance (MDR) in breast cancer. This study aimed to evaluate the potential of CIAPIN1 gene silencing by RNA interference (RNAi) as a treatment for drug-resistant breast cancer and to investigate the effect of CIAPIN1 on the drug resistance of breast cancer in vivo. We used lentivirus-vector-based RNAi to knock down CIAPIN1 in nude mice bearing MDR breast cancer tumors and found that lentivirus-vector-mediated silencing of CIAPIN1 could efficiently and significantly inhibit tumor growth when combined with chemotherapy in vivo. Furthermore, Western blot analysis showed that both CIAPIN1 and P-glycoprotein expression were efficiently downregulated, and P53 was upregulated, after RNAi. Therefore, we concluded that lentivirus-vector-mediated RNAi targeting of CIAPIN1 is a potential approach to reverse MDR of breast cancer. In addition, CIAPIN1 may participate in MDR of breast cancer by regulating P-glycoprotein and P53 expression.     

Reticular and plexiform perineurioma: clinicopathological and immunohistochemical analysis of two cases and review of perineurial neoplasms of skin and soft tissues

Perineurioma represents a recently described and relatively rare neoplasm in the spectrum of benign peripheral nerve sheath tumours composed of perineurial cells staining immunohistochemically positive for epithelial membrane antigen (EMA). In addition to intraneural, extraneural and sclerosing perineurioma, rare variants of perineurioma may occur, and their knowledge is important in the differential diagnosis of mesenchymal tumours of different lines of differentiation and clinically more aggressive neoplasms. We present a case of deep-seated reticular perineurioma arising on the upper arm of a 34-year-old female and a case of a dermal plexiform perineurioma arising on the lower lip of a 60-year-old female. The diagnosis was confirmed in both cases immunohistochemically; neoplastic cells stained positively for EMA and for the newly described perineurial markers, claudin-1 and glut-1. The morphological spectrum and the differential diagnosis of perineurial neoplasms of skin and soft tissues are discussed.     

Molecular cloning, characterization and expression analysis of two novel Tolls (LvToll2 and LvToll3) and three putative Spätzle-like Toll ligands (LvSpz1-3) from Litopenaeus vannamei

Toll-like receptor-mediated NF-κB pathways are essential for inducing immune related-gene expression in the defense against bacterial, fungal and viral infections in insects and mammals. Although a Toll receptor (LvToll1) was cloned in Litopenaeus vannamei, relatively little is known about other types of Toll-like receptors and their endogenous cytokine-like ligand, Spätzle. Here, we report two novel Toll-like receptors (LvToll2 and LvToll3) and three Spätzle-like proteins (LvSpz1-3) from L. vannamei. LvToll2 has 1009 residues with an extracellular domain containing 18 leucine-rich repeats (LRRs) and a cytoplasmic Toll/interleukin-1 receptor (TIR) domain of 139 residues. LvToll3 is 1244 residues long with an extracellular domain containing 23 LRRs and a cytoplasmic TIR domain of 138 residues. The Spätzle-like proteins LvSpz1, LvSpz2 and LvSpz3 are 237, 245 and 275 residues in length, respectively, and all of them have a putative C-terminal cystine-knot domain. In Drosophila Schneider 2 (S2) cells, LvToll1 and LvToll3 were localized to the membrane and cytoplasm, and LvToll2 was confined to the cytoplasm. In Drosophila S2 cells, LvToll2 could significantly activate the promoters of NF-κB-pathway-controlled antimicrobial peptide genes, whereas LvToll1 and LvToll3 had no effect on them. LvSpz1 exerted some degree of inhibition on the promoter activities of Drosophila Attacin A and L. vannamei Penaeidin4. LvSpz3 also inhibited the Drosophila Attacin A promoter, but LvSpz2 could only slightly activate it. LvToll1, LvToll2 and LvToll3 were constitutive expressed in various tissues, while LvSpz1, LvSpz2 and LvSpz3 exhibited tissue-specific expression in the epithelium, eyestalk, intestine, gill and muscle. In the gill, after Vibrio alginolyticus challenge, LvToll1 was upregulated, but LvToll2 and LvToll3 showed no obvious changes. LvSpz1 and LvSpz3 were also strongly induced by V. alginolyticus challenge, but LvSpz2 only showed a slight downregulation. In the gill, after white spot syndrome virus (WSSV) challenge, LvToll1, LvToll2, LvToll3, LvSpz1 and LvSpz3 were upregulated, but LvSpz2 showed no obvious change, except for a slight downregulation at 12 h post-injection of WSSV. These findings might be valuable in understanding the innate immune signal pathways of shrimp and enabling future studies on the host-pathogen interactions in V. alginolyticus and WSSV infections.     

Shrimp NF-κB binds to the immediate-early gene ie1 promoter of white spot syndrome virus and upregulates its activity

The immediate-early gene ie1 carried by white spot syndrome virus (WSSV) exhibits very strong promoter activity and expresses highly throughout the infection cycle. Here we identified a NF-κB binding motif in the ie1 promoter region. Electrophoretic mobility shift assays indicated that the recombinant Rel homology domain (RHD) of shrimp NF-κB homolog LvRelish bound to the putative NF-κB site in the ie1 promoter. A transactivity assay of the WSSV ie1 promoter in Drosophila Schneider 2 cells demonstrated that LvRelish could increase ie1 promoter activity. These results show that shrimp NF-κB homolog LvRelish transactivates WSSV ie1 gene expression and contributes to its high promoter activity. Further transactivation assays showed that WSSV IE1 protein expression upregulated the promoter activities of WSSV ie1 gene and antimicrobial peptide genes regulated by the NF-κB system. We suggested that WSSV may annex the shrimp NF-κB system, which it uses to enhance the expression of viral immediate-early genes.     

Evidence for an association between increased oxidative stress and derangement of FOXO1 signaling in tumorigenesis of a cellular angiofibroma with monoallelic 13q14: a case report

Cellular angiofibroma (CAF) is a rare soft tissue tumor characterized by random arrangement of spindle tumor cells in the stroma with short collagen bundles and thick- and hyalinized small vessels. CAFs share histological characteristics with spindle cell lipomas and mammary type myofibroblastomas. Because these tumors harbor monoallelic 13q14, common genetic and molecular mechanism for tumorigenesis is presumed. In this study, we reported a case of CAF in a 69-year-old man with monoallelic 13q14. Immunohistochemical analysis revealed that FOXO1, which is located in chromosome 13q14, was not expressed in the tumor. We also detected oxidative stress markers and found p38 MAPK activation, which is often induced by cellular stressors such as reactive oxygen species (ROS). Because FOXO1 induces the expression of genes encoding enzymes that generate antioxidants, oxidative stress induced by loss of FOXO1 expression may be common among CAFs, spindle cell lipomas, and mammary type myofibroblastomas.     

MED12 exon 2 mutations in histopathological uterine leiomyoma variants

Uterine leiomyomas, or fibroids, are the most common human tumors. Based on histopathology, they can be divided into common leiomyomas and various relatively rare subtypes that mimic malignancy in one or more aspects. Recently, we showed that exon 2 of mediator complex subunit 12 (MED12) is mutated in up to 70% of common fibroids. To investigate the frequency of MED12 exon 2 mutations in histopathological uterine leiomyoma variants, we screened altogether 206 lesions, including 69 histopathologically common leiomyomas, 59 cellular (23 cellular and 36 highly cellular), 18 atypical and 26 mitotically active leiomyomas, as well as 34 uterine fibroid samples from 14 hereditary leiomyomatosis and renal cell cancer patients with a heterozygous germ line mutation in fumarate hydratase (FH). The uterine leiomyoma variants harbored MED12 exon 2 mutations significantly less frequently than common leiomyomas (P=2.93 × 10⁻⁸). In all, 6 mutations were detected among cellular fibroids (6/67; 8.96%), 3 among atypical fibroids (3/18; 16.67%) and 10 among mitotically active fibroids (10/26; 38.46%). Only mitotically active fibroids displayed a mutation frequency that was not statistically different from common leiomyomas (P=0.11). Three MED12 exon 2 mutations were detected among 34 tumors with a heterozygous germ line FH mutation (P=5.28 × 10⁻⁷). None of these tumors displayed biallelic inactivation of FH. Our results suggest that MED12 mutation positivity is a key characteristic of common leiomyomas. Cellular and atypical fibroids, in particular, may arise through different molecular mechanisms. The results also propose that MED12 and biallelic FH mutations may be mutually exclusive.