Pyruvate carboxylase is critical for non-small-cell lung cancer proliferation

Anabolic biosynthesis requires precursors supplied by the Krebs cycle, which in turn requires anaplerosis to replenish precursor intermediates. The major anaplerotic sources are pyruvate and glutamine, which require the activity of pyruvate carboxylase (PC) and glutaminase 1 (GLS1), respectively. Due to their rapid proliferation, cancer cells have increased anabolic and energy demands; however, different cancer cell types exhibit differential requirements for PC- and GLS-mediated pathways for anaplerosis and cell proliferation. Here, we infused patients with early-stage non-small-cell lung cancer (NSCLC) with uniformly 13C-labeled glucose before tissue resection and determined that the cancerous tissues in these patients had enhanced PC activity. Freshly resected paired lung tissue slices cultured in 13C6-glucose or 13C5,15N2-glutamine tracers confirmed selective activation of PC over GLS in NSCLC. Compared with noncancerous tissues, PC expression was greatly enhanced in cancerous tissues, whereas GLS1 expression showed no trend. Moreover, immunohistochemical analysis of paired lung tissues showed PC overexpression in cancer cells rather than in stromal cells of tumor tissues. PC knockdown induced multinucleation, decreased cell proliferation and colony formation in human NSCLC cells, and reduced tumor growth in a mouse xenograft model. Growth inhibition was accompanied by perturbed Krebs cycle activity, inhibition of lipid and nucleotide biosynthesis, and altered glutathione homeostasis. These findings indicate that PC-mediated anaplerosis in early-stage NSCLC is required for tumor survival and proliferation.

Hepatoid adenocarcinoma of the lung: report of five cases and review of the literature

The current diagnostic criteria for hepatoid adenocarcinoma of lung include typical acinar or papillary adenocarcinoma and a component resembling hepatocellular carcinoma and expressing α-fetoprotein (AFP). Distinguishing hepatoid adenocarcinoma of lung from hepatocellular carcinoma metastatic to lung is difficult in patients with both lung and liver masses and in patients at risk for lung and liver cancer because of smoking and viral hepatitis, respectively. We studied morphologic features of hepatoid adenocarcinoma of lung and established an immunohistochemical panel to facilitate distinction of hepatoid adenocarcinoma of lung from hepatocellular carcinoma metastatic to lung. Five cases of hepatoid adenocarcinoma of lung were stained with hematoxylin and eosin and mucicarmine for histomorphologic evaluation. The 14-marker immunohistochemical profile was established for hepatoid adenocarcinoma of lung and compared with that of hepatocellular carcinoma. Two cases of hepatoid adenocarcinoma of lung had signet-ring cell components. Three cases were pure hepatoid adenocarcinoma without components of acinar or papillary adenocarcinoma, signet-ring cells or neuroendocrine carcinoma. Like hepatocellular carcinoma, hepatoid adenocarcinoma of lung expresses CK8 (5/5), CK18 (5/5), AFP (3/5) and HepPar1 (5/5), shows cytoplasmic staining with TTF-1 (5/5) and does not express CK14 (0/5). Unlike hepatocellular carcinoma, it expresses CK5/6 (1/5), CK7 (3/5), CK19 (4/5), CK20 (1/5), HEA125 (5/5), MOC31 (5/5), monoclonal CEA (3/5) and napsin A (1/5). An immunohistochemical panel that includes a variety of cytokeratins, monoclonal CEA and EpCAM markers (HEA125 and MOC31) facilitates distinction of hepatoid adenocarcinoma of lung from hepatocellular carcinoma metastatic to lung, especially when correlated with clinical and radiologic findings. We propose modification of the current diagnostic criteria for hepatoid adenocarcinoma of lung. Tumor composition can be either pure hepatoid adenocarcinoma or hepatoid adenocarcinoma with components of typical acinar or papillary adenocarcinoma, signet-ring cells or neuroendocrine carcinoma. AFP expression is not requisite for diagnosis as long as other markers of hepatic differentiation are expressed.

Intravascular large B-cell lymphoma presenting as acute hemorrhagic cerebral infarct with delirium

Intravascular large B-cell lymphoma (IVLBCL) is a cumbersome diagnosis to make in vivo, particularly because of its elusive nature and ability to be a relatively nonspecific 'great mimicker'. Although it frequently has skin manifestations, it often escapes diagnosis due to its angiotrophism and predilection for vessels that are difficult to biopsy (e.g., cerebral vasculature). IVLBCL can involve the vasculature of virtually any organ but typically spares the lymph nodes themselves, and likely due to defects in adhesion molecules, remains stationary in the vessels. Histologically, the malignant lymphocytes are large and mitotically active with prominent nucleoli. Immunohistochemically, the cells stain as B-cells. The disease has an overall poor prognosis. Here we present a case of IVLBCL diagnosed at autopsy that presented as a hemorrhagic frontal lobe infarct, which progressed to delirium.

Tumor-associated primo vascular system is derived from xenograft, not host

The primo vascular system (PVS), which is composed of very small primo-vessels (PV) and primo-nodes (PN), has recently emerged as a third component of circulatory system. Here, we report the presence of a tumor derived PVS in murine xenografts of human histiocytic lymphoma (U937) in close proximity to the tumor. Within this system, PNs are small (~500-600 μM diameter) membranous sac-like structures which contain numerous small cells which can be demonstrated by DAPI staining. Hematoxylin and Eosin (H&E) staining of the peri-tumoral PVS shows the presence of loose structures lined by fibroblasts but filled with dense fibers, cells, lacunae and nerve-like structures. The origin and type of cells within the PVS was characterized by immunostaining with antibodies for CD68, CD45 and lysozyme. The results of these studies reveal that the PVS of the xenograft originates from the human U937 tumor cells. qRT-PCR analysis of mRNA isolated from PVS cells reveals a striking predominance of human, rather than mouse, sequences. Of particular interest, human stem cell specific transcription factors were overexpressed, most notably KLF4, an upstream regulator of NANOG which maintains the pluripotent and undifferentiated state of stem cells. These results suggest that the cells present within the PVS are derived from the human xenograft and suggests that the primo-vessels associated with the xenografted tumor may provide a safe haven for a select population of cancer stem cells. Further understanding of the biological properties of these cells may allow the development of new anti-cancer interventions.

Tartrate-resistant acid phosphatase 5a in sarcoidosis: further evidence for a novel macrophage biomarker in chronic inflammation

BACKGROUND/PURPOSE

Tartrate-resistant acid phosphatase (TRACP) 5a is expressed strongly in inflammatory macrophages (MΦ). Serum TRACP5a is elevated in rheumatoid arthritis patients with extra-articular manifestations of rheumatoid nodules, in a percentage of patients with end-stage chronic kidney disease, and may be a risk marker for acute myocardial infarction. This proof-of-concept study was undertaken in patients with sarcoidosis to further substantiate our hypothesis that TRACP5a protein is a biomarker for macrophages in other chronic inflammatory diseases.

METHODS

Immunohistochemical staining for TRACP5a and CD68 was performed in tissues of 19 patients with sarcoidosis. We also measured circulating TRACP5a protein and other inflammation biomarkers including interkeukin-6, angiotensin-converting enzyme, and C-reactive protein in 13 patients. Twenty healthy age-matched nonsmoking individuals were used as the reference group.

RESULTS

All sarcoidosis tissues showed strong staining for TRACP5a and CD68 in the non-caseating granulomatous lesions and localized specifically to MΦ, multinucleate giant cells, and epithelioid MΦ. Serum TRACP5a protein was elevated significantly in active sarcoidosis patients compared with the control group, and levels fluctuated with disease activity in one patient studied longitudinally.

CONCLUSION

TRACP5a protein is expressed abundantly in the granulomatous tissues and may be elevated in a significant proportion of sarcoidosis patients. These findings further support our hypothesis that serum TRACP5a is derived from systemic inflammatory MΦ and thereby may be a biomarker of inflammation for sarcoidosis and also reflect its disease activity.

Effect of freeze-dried berries on the development of reflux-induced esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma in humans is increasing more rapidly than any other malignancy in the United States. Animal studies have demonstrated the efficacy of freeze-dried berry supplementation on carcinogen-induced esophageal squamous cell carcinoma in rats; however, no such studies have been done in esophagoduodenal anastomosis (EDA), an animal model for reflux-induced esophageal adenocarcinoma (EAC) development. Eight-week-old male Sprague-Dawley rats were randomized into 3 groups: EDA + control diet (EDA-CD; n = 10); EDA + 2.5% black raspberry diet (EDA-BRB; n = 11) and EDA + 2.5% blueberry diet (EDA-BB; n = 12). After 2 wk of feeding the respective diets, the rats underwent EDA surgery to induce gastroesophageal reflux and then continued the diet. Measurement of feed intake suggested that all EDA-operated animals had lower feed intake starting at 10 wk after surgery and this was significant close to termination at 24 wk. There were no significant differences in either reflux esophagitis (RE), intestinal metaplasia (IM) (70% in CD, 64% in BRB, and 66% in BB; P = 0.1) or EAC incidence (30% for CD, 34% for BRB, and 25% for BB; P = 0.2) with supplementation. Berry diets did not alter COX-2 levels, but BB diet significantly reduced MnSOD levels (1.23 ± 0.2) compared to control diet (2.05 ± 0.14; P < 0.05). We conclude that a dietary supplementation of freeze-dried BRB and BB at 2.5% (w/w) was not effective in the prevention of reflux-induced esophageal adenocarcinoma in this EDA animal model.

Tartrate-resistant acid phosphatase as an immunohistochemical marker for inflammatory macrophages

Human serum contains 2 isoforms of type-5 tartrate-resistant acid phosphatase (TRACP): 5a and 5b. TRACP-5b is osteoclastic. Our goal was to determine if serum TRACP-5a could originate from inflammatory macrophages (MPhi). We stained 246 paraffin-embedded tissue samples for TRACP using monoclonal antibody 9C5 (mab9C5) to isoforms 5a and 5b and a novel mab220 specific to isoform 5a. CD68 and lysozyme were also stained. MPhi of chronic and granulomatous inflammation and in tissues that undergo strong antigenic stimulation were strongly positive for TRACP, more so with mab220 than with mab9C5. Noninflammatory MPhi in lymph node sinuses or germinal centers and red pulp MPhi of spleen were weak or negative for TRACP. Marginal zone lymphocytes and sebaceous glands of skin were weakly positive for TRACP. Tissue mast cells displayed strong TRACP staining. Neuroendocrine cells of gastrointestinal tissues were strongly immunoreactive with mab9C5 but negative with mab220. Restricted expression of TRACP primarily in inflammatory MPhi supports our hypothesis that circulating TRACP-5a could be a biomarker of chronic inflammatory disease activity.

Clone-specific anti-CD45 blocking factor in patient plasma

We observed inhibition of anti-CD45, but not anti-CD3, -CD4, or -CD8 staining in the whole blood of an individual clinical specimen. Subsequent experiments demonstrated the presence of a plasma factor, which likewise blocked CD45 staining of third party lymphocytes. The blocking activity was anti-CD45 clone (2D1) specific. Experiments utilizing immunoabsorption, immunofluorescence, and commercial blocking reagents failed to provide evidence for identifying blocking factor as heterophilic antibody. Biochemical identification of blocking factor was not accomplished.

Tubal gestation and schistosomiasis: a case report

BACKGROUND

Schistosomal infections of the female reproductive tract are common in countries where the parasite is endemic. Serious complications, such as ectopic pregnancy and infertility, may arise in patients with gynecologic schistosomiasis.

CASE

A primiparous, African woman presented with vaginal bleeding and was found to have an ectopic pregnancy. Laparoscopy revealed distorted pelvic anatomy due to dense adhesions. Pathologic examination confirmed an ectopic pregnancy and identified Schistosoma haematobium ova in the patient's fallopian tube. Urine examination was confirmatory, and the patient was treated and referred for fertility counseling.

CONCLUSION

Clinicians should consider schistosomiasis as a possible etiology for gynecologic complaints, including serious complications such as ectopic pregnancy and infertility, in patients from endemic regions.

Positive pregnancy tests in a nongravid, premenopausal woman due to hCG beta-chain production by multiple myeloma

Positive pregnancy test results occurred in a nongravid, premenopausal woman while she was receiving chemotherapy for multiple myeloma. We tested 2 hypotheses to account for this finding: (1) Heterophil antibodies caused positive interference in the immunoassays. (2) Genuine human chorionic gonadotropin (hCG) originated from a nonsyncytiotrophoblastic source. Paraprotein was eliminated as a source of positive interference because 3 different instruments with unique capture and signal antibodies gave similar results (83, 90, and 97 mIU/mL [83, 90, and 97 IU/L]). Human antimouse antibodies (HAMAs) were unlikely to cause positive interference because immunoreactivity was maintained after serum was treated to neutralize heterophil antibodies. Immunoassays performed after gel filtration of serum indicated that immunoreactivity was due to genuine hCG. The high-molecular-weight fraction (heterophil antibody) had 6 mIU/mL (6 IU/L) of hCG. The low-molecular-weight fraction (hCG) had 86 mIU/mL (86 IU/L) of hCG. Immunohistochemical stains revealed that myeloma cells expressed immunoreactive hCG. Hence, multiple myeloma caused positive pregnancy test results in a nongravid woman.

Sinus histiocytosis with massive lymphadenopathy and Langerhans cell histiocytosis express the cellular adhesion molecule CD31

Context.-We investigated expression of the adhesion molecule CD31 in sinus histiocytosis with massive lymphadenopathy (SHML) and Langerhans cell histiocytosis (LCH) because (1) SHML and LCH cells express a variety of cellular adhesion molecules and (2) SHML has been characterized as a reactive histiocytic proliferation, and tissue macrophages (histiocytes) are known to express CD31. Objective.-The purpose of this study was to determine whether SHML and LCH cells express CD31 and whether dual staining with CD31 and S100 facilitates diagnosis of these disease states. Methods.-Formalin-fixed, paraffin-embedded archival tissues were immunohistochemically stained via the labeled streptavidin-biotin method using antibodies against CD31 and S100 protein after heat-induced epitope retrieval. Archival tissues included SHML (n = 2), LCH (n = 10), malignant melanoma (n = 5), sinus hyperplasia (n = 4), granulomas (n = 4), granular cell tumor (n = 6), and normal skin (n = 4). Results.-Normal Langerhans cells in the epidermis were CD31(-)/S100(+); neoplastic Langerhans cells in LCH were CD31(+)/S100(+). Histiocytes in granulomas and in sinus hyperplasia were CD31(+)/S100(-); abnormal histiocytes in SHML were CD31(+)/S100(+). S100(+) tumors (malignant melanoma and granular cell tumor) were CD31(-). Conclusions.-The spectrum of cell types that express CD31 is expanded to include SHML and LCH. We speculate that up-regulation of CD31 in neoplastic Langerhans cells contributes to the migratory capability of LCH cells. CD31 may be a useful nonlysosomal marker of macrophages and their neoplastic counterparts (true histiocytic sarcomas). An immunohistochemical staining panel that includes CD31 and S100 facilitates the diagnosis of SHML and LCH.

Vascular inflammation (vasculitis) in sweet syndrome: a clinicopathologic study of 28 biopsy specimens from 21 patients

BACKGROUND

Sweet syndrome is characterized by painful, erythematous plaques of rapid onset accompanied by fever. Absence of vasculitis is a histologic criterion for diagnosis. However, recent reports suggest that vasculitis should not exclude the diagnosis. We hypothesized that vasculitis can occur in Sweet syndrome and that it represents an epiphenomenon rather than a primary immune-mediated process.

DESIGN

Skin biopsy specimens from patients with Sweet syndrome were reviewed to determine the prevalence of vasculitis. The clinicopathologic features of cases with vasculitis were evaluated for statistically significant associations. Specimens with vasculitis underwent immunofluorescence staining.

SETTING

University department of dermatology, university hospital, and private practice.

PATIENTS

Medical records and biopsy specimens of 21 patients meeting diagnostic criteria for Sweet syndrome were reviewed.

INTERVENTIONS

None.

RESULTS

The prevalence of vasculitis was 29% (6 of 21 patients). There was a significant association of vasculitis with lesions of longer duration (P =.02). Vascular immunoglobulin and complement could not be demonstrated in cases of Sweet syndrome with vasculitis.

CONCLUSIONS

Vasculitis is not a primary, immune-mediated process in Sweet syndrome but occurs secondary to noxious products released from neutrophils. Blood vessels in lesions of longer duration are more likely to develop vasculitis than those of shorter duration because of prolonged exposure to noxious metabolites. Vasculitis does not exclude a diagnosis of Sweet syndrome.

Comparison of methylene blue-directed biopsies and conventional biopsies in the detection of intestinal metaplasia and dysplasia in Barrett's esophagus: a preliminary study

BACKGROUND

The diagnostic advantage of methylene blue (MB) chromoendoscopy in Barrett's esophagus is unclear.

METHODS

Patients with columnar-lined esophagus (CLE) were enrolled into a prospective, randomized crossover trial of MB-directed biopsy versus conventional biopsy.

RESULTS

Forty-seven patients (19 long-segment CLE; 28 short-segment CLE) were enrolled and underwent MB-directed biopsy. Sensitivity and specificity of MB for specialized intestinal metaplasia were 53% and 51%, respectively. Sensitivity and specificity of MB for dysplasia were 51% and 48%, respectively. Thirty-five patients (15 long-segment CLE; 20 short-segment CLE) completed the crossover trial. Relative frequencies for specialized intestinal metaplasia were 73% and 71% from MB-directed and conventional biopsy specimens, respectively (p = 0.73). Relative frequencies for dysplasia were 20% and 18% from MB-directed and conventional biopsy specimens, respectively (p = 0.65). In patients with long-segment CLE, dysplasia was diagnosed in 10 patients with MB and 7 patients with conventional biopsy methods (p = 0.25). The number of biopsy specimens per EGD was greater with MB, which may have influenced the diagnosis. Histologically, the grade of dysplasia was indefinite/low in nearly all of the dysplastic specimens.

CONCLUSIONS

Results of MB-directed biopsy were similar to conventional biopsy in detecting specialized intestinal metaplasia and indefinite/low-grade dysplasia. MB was not useful in short-segment Barrett's esophagus.

Pure red cell aplasia due to parvovirus B19 in a patient treated with rituximab

Rituximab is a chimeric monoclonal antibody directed against CD20 and used in the treatment of B-cell non-Hodgkin's lymphoma. Due to its ability to deplete B lymphocytes, rituximab can interfere with humoral immunity, causing it to be suppressed for several months after treatment. The reported case depicts a serious consequence of this effect of rituximab therapy: pure red cell aplasia resulting from chronic parvovirus B19 infection. The point of interest in this case is not only the association between rituximab therapy and pure red cell aplasia, but the diagnostic and therapeutic utility of the knowledge of parvovirus B19 as the likely etiologic link between the two. Given the known efficacy of intravenous immunoglobulin (IVIg) in the treatment of chronic parvovirus B19 infection, this therapy can cure some of these patients and successfully render most others transfusion-independent until recovery of their own humoral immune system.

CML blast crisis resulting in biliary obstruction following BMT

Allogeneic BMT is the treatment of choice for various hematologic malignancies. Despite careful patient scrutiny, a large number of patients experience significant morbidity and mortality due to procedure-related toxicity. Hepatobiliary toxicity presenting as biliary cholestasis, due to the preparative regimen (ie venoocclusive disease), supportive pharmaceuticals, and/or GVHD have been implicated. We report a unique cause of cholestasis in a patient undergoing BMT for CML. The cholestasis was found to be secondary to relapsed leukemia, which resulted in a granulocytic sarcoma obstructing the biliary ductal system.