CDX2 is a homeobox domain-containing transcription factor that is important in the development and differentiation of the intestines. Based on recent studies, CDX2 expression is immunohistochemically detectable in normal colonic enterocytes and is retained in most, but not all, colorectal adenocarcinomas. CDX2 expression has also been documented in a subset of adenocarcinomas arising in the stomach, esophagus and ovary. In this study, we examined CDX2 expression in a series of large tissue microarrays representing 4652 samples of normal and neoplastic tissues. Strong nuclear staining for CDX2 was observed in 97.9% of 140 colonic adenomas, 85.7% of 1109 colonic adenocarcinomas overall and 81.8% of 55 mucinous variants. There was no significant difference in the staining of well-differentiated (96%) and moderately differentiated tumors (90.8%, P ¼ 0.18), but poorly differentiated tumors showed reduced overall expression (56.0%, Po0.000001). Correspondingly, there was an inverse correlation between CDX2 expression and tumor stage, with a significant decrease in staining between pT2 and pT3 tumors (95.8 vs 89.0%, Po0.012), and between pT3 and pT4 tumors (89.0 vs 79.8%, Po0.016). Analysis of 140 locally advanced, CDX2-positive colorectal adenocarcinomas coarrayed with their matching lymph node metastases revealed that expression of this marker was retained in 82.1% of the metastases. Consistent with previous reports, CDX2 staining was observed in gastric adenocarcinomas (n ¼ 71), more commonly in the intestinal-type than the diffuse-type (28.9 vs 11.5%, Po0.05). Occasional ovarian carcinomas were positive for CDX2, including mucinous (10.5%), endometrioid (9.3%) and serous variants (2%), but expression was either very rare or absent in primary carcinomas of the lung, breast, thyroid, pancreas, liver, gallbladder, kidney, endometrium and urinary bladder. A low frequency of CDX2 expression in pancreatic and biliary carcinomas observed on the microarrays was pursued further by comparing these tumors with ampullary adenocarcinomas on conventional sections. Ampullary adenocarcinomas were more commonly positive for CDX2 (19/24, 79%) than cholangiocarcinomas (1/11, 9%) and pancreatic carcinomas (3/20, 15%). In summary, CDX2 is a sensitive and specific marker for colorectal adenocarcinoma, although its expression is decreased among higher grade and stage tumors, and it is not invariably present in metastases from positive primaries. CDX2 may also be helpful in distinguishing adenocarcinomas of the ampulla from those arising in the pancreas and biliary tree.

No abstract

Recent interest in the health consequences of ricin as a weapon of terrorism has led us to investigate the effects of ricin on cells in vitro and in mice. Our previous studies showed that depurination of the 28S rRNA by ricin results in the inhibition of translation and the coordinate activation of the stress-activated protein kinases JNK and p38 MAPK. In RAW 264.7 macrophages, ricin induced the activation of ERK, JNK, and p38 MAPK, the accumulation of mRNA encoding tumor necrosis factor (TNF)-alpha, interleukin (IL)-1, the transcription factors c-Fos, c-Jun, and EGR1, and the appearance of TNF-alpha protein in the culture medium. Using specific inhibitors of MAPKs, we demonstrated the nonredundant roles of the individual MAPKs in mediating proinflammatory gene activation in response to ricin. Similarly, the intravenous administration of ricin to mice led to the activation of ERK, JNK, and p38 MAPK in the kidneys, and increases in plasma-borne TNF-alpha, IL-1beta, and IL-6. Ricin-injected mice developed the hallmarks of hemolytic uremic syndrome, including thrombotic microangiopathy, hemolytic anemia, thrombocytopenia, and acute renal failure. Microarray analyses demonstrated a massive proinflammatory transcriptional response in the kidneys, coincidental with the symptoms of hemolytic uremic syndrome. Therapeutic management of the inflammatory response may affect the outcome of intoxication by ricin.

Objective To assess whether primary and secondary vestibulodynia represent different pathologic pathways. Methods This was an analysis of archived vestibulectomy specimens from 88 premenopausal women with vestibulodynia (2002–2008). Patient records were reviewed to classify the type of vestibulodynia, duration of symptoms, and hormone status. Histologic sections were stained for hematoxylin and eosin to grade inflammation, S100 to highlight nerves, CD117 for mast cells, estrogen receptor α, and progesterone receptor. Differences between primary and secondary vestibulodynia were tested by t-tests, chi-square analysis, linear and logistic regression. Results Primary vestibulodynia showed significant neural hypertrophy and hyperplasia (p=0.02, adjusted odds ratio 3.01 [1.2–7.6]) and increased progesterone receptor nuclear immunostaining (p=0.004, adjusted odds ratio 3.94 [1.6–9.9]) compared with secondary vestibulodynia. estrogen receptor α expression was also greater in primary vestibulodynia when symptom diagnosis was less than 5 years (p=0.004, adjusted odds ratio 5.53 [1.71–17.91]). Conclusions Primary and secondary vestibulodynia have significantly different histologic features, suggesting that they may have separate mechanistic pathways. Clinically, this may mean the discovery of distinct conditions.

In view of the possibility that ricin may be used as a bioweapon against human populations, we examined the pathological consequences that occur in mice after introduction of ricin into the pulmonary system. Intratracheal instillation of a lethal dose of ricin (20 g/100 g body weight) resulted in a hemorrhagic inflammatory response in multiple organs, accompanied by activation of mitogen-activated protein kinases, increased synthesis of proinflammatory RNA transcripts, and increased levels of circulating cytokines and chemokines. A sublethal dose of instilled ricin (2 g/100 g body weight) induced a similar response in lungs but did not cause detectable damage in other organs. Lungs of mice that recovered from a sublethal dose of ricin displayed evidence of fibrosis and residual damage. A lethal dose of ricin caused accumulation of proinflammatory RNA transcripts and substantial damage to 28S rRNA of multiple organs, including lung, kidney, spleen, liver, and blood, demonstrating that instilled ricin gained access to the circulation. The kidneys of mice instilled with a lethal dose of ricin showed accumulation of fibrin/fibrinogen in glomerular capillaries, increased numbers of glomerular leukocytes, and impairment of kidney function. A sublethal dose of ricin failed to induce damage to 28S rRNA in kidney or other extrapulmonary organs.

Because of its lethal effects, ease of preparation, and ability to be delivered by aerosolization, ricin has been developed as a lethal weapon by various terrorist groups. When introduced into the pulmonary system of rodents, ricin causes pathological changes in the lung that are known to occur in acute respiratory distress syndrome (ARDS). Early response cytokines such as TNF-alpha and IL-1 are known to play a critical role in the pathogenesis of ARDS. Ricin induces the release of these pro-inflammatory cytokines and the transcriptional activation of the genes that encode them in vitro and in vivo. Macrophages, considered to act as upstream regulators of inflammatory cascades, may play a central role in the pathogenesis and the development of ricin-induced ARDS because of their ability to make and secrete pro-inflammatory cytokines. Exposure of primary macrophages to ricin in vitro led to activation of stress-activated protein kinases, increased expression of pro-inflammatory mRNA transcripts, subsequent increase in the synthesis and secretion of TNF-alpha, and apoptotic cell death. Interestingly, macrophages required the engagement of the apoptotic cascade for the maximal synthesis and release of some pro-inflammatory mediators. This work identifies a cross talk between the apoptotic and inflammatory signaling pathways induced by ricin in primary macrophages.

Wong J, Korcheva V, Jacoby DB, Magun BE. Proinflammatory responses of human airway cells to ricin involve stressactivated protein kinases and NF-B.

Rapid elimination of virus-infected cells by apoptosis is an efficient anti-viral strategy. Double-stranded RNA (dsRNA), a viral product, is potently and rapidly apoptogenic in susceptible cells. Caspase 8 plays an important role in the dsRNA-induced apoptosis; however, the mechanisms of caspase 8 activation in response to dsRNA are unknown. We demonstrate here that, in HeLa cells, the dsRNA-triggered activation of caspase 8 is independent of ongoing proteins synthesis (and is, therefore, independent of changes in pro- and anti-apoptotic gene expression) and involves the formation of multiprotein dsRNA-triggered death inducing signaling complexes (dsRNA-DISCs). DsRNA-DISCs contain FADD, TRADD, and caspase 8; however, several experimental approaches suggest that death ligands and death receptors (such as Fas/Apo1 and DR4/Apo2) are not involved in the formation of dsRNA-DISCs.